diff --git a/docs/source/conf.py b/docs/source/conf.py
index 925d131..b94ce2d 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 #
 # plone.app.discussion documentation build configuration file, created by
 # sphinx-quickstart on Thu Mar 18 10:17:15 2010.
@@ -24,184 +23,190 @@ import sys
 
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = ['sphinx.ext.autodoc',
-              'sphinx.ext.doctest',
-              'sphinx.ext.intersphinx',
-              'sphinx.ext.todo',
-              'sphinx.ext.coverage',
-              'repoze.sphinx.autointerface'
-              ]
+extensions = [
+    "sphinx.ext.autodoc",
+    "sphinx.ext.doctest",
+    "sphinx.ext.intersphinx",
+    "sphinx.ext.todo",
+    "sphinx.ext.coverage",
+    "repoze.sphinx.autointerface",
+]
 
 
 # Add any paths that contain templates here, relative to this directory.
-templates_path = ['_templates']
+templates_path = ["_templates"]
 
 # The suffix of source filenames.
-source_suffix = '.txt'
+source_suffix = ".txt"
 
 # The encoding of source files.
-#source_encoding = 'utf-8'
+# source_encoding = 'utf-8'
 
 # The master toctree document.
-master_doc = 'index'
+master_doc = "index"
 
 # General information about the project.
-project = u'plone.app.discussion'
-copyright = u'2010, Timo Stollenwerk - Plone Foundation'
+project = "plone.app.discussion"
+copyright = "2010, Timo Stollenwerk - Plone Foundation"
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
 # built documents.
 #
 # The short X.Y version.
-version = '2.0'
+version = "2.0"
 # The full version, including alpha/beta/rc tags.
-release = '2.0'
+release = "2.0"
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
-#language = None
+# language = None
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:
-#today = ''
+# today = ''
 # Else, today_fmt is used as the format for a strftime call.
-#today_fmt = '%B %d, %Y'
+# today_fmt = '%B %d, %Y'
 
 # List of documents that shouldn't be included in the build.
-#unused_docs = []
+# unused_docs = []
 
 # List of directories, relative to source directory, that shouldn't be searched
 # for source files.
 exclude_trees = []
 
 # The reST default role (used for this markup: `text`) to use for all documents.
-#default_role = None
+# default_role = None
 
 # If true, '()' will be appended to :func: etc. cross-reference text.
-#add_function_parentheses = True
+# add_function_parentheses = True
 
 # If true, the current module name will be prepended to all description
 # unit titles (such as .. function::).
-#add_module_names = True
+# add_module_names = True
 
 # If true, sectionauthor and moduleauthor directives will be shown in the
 # output. They are ignored by default.
-#show_authors = False
+# show_authors = False
 
 # The name of the Pygments (syntax highlighting) style to use.
-pygments_style = 'sphinx'
+pygments_style = "sphinx"
 
 # A list of ignored prefixes for module index sorting.
-#modindex_common_prefix = []
+# modindex_common_prefix = []
 
 
 # -- Options for HTML output ---------------------------------------------
 
 # The theme to use for HTML and HTML Help pages.  Major themes that come with
 # Sphinx are currently 'default' and 'sphinxdoc'.
-#html_theme = 'plone'
+# html_theme = 'plone'
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
 # documentation.
-#html_theme_options = {}
+# html_theme_options = {}
 
 # Add any paths that contain custom themes here, relative to this directory.
-html_theme_path = ['_themes']
+html_theme_path = ["_themes"]
 
 # The name for this set of Sphinx documents.  If None, it defaults to
 # "<project> v<release> documentation".
-#html_title = None
+# html_title = None
 
 # A shorter title for the navigation bar.  Default is the same as html_title.
-#html_short_title = None
+# html_short_title = None
 
 # The name of an image file (relative to this directory) to place at the top
 # of the sidebar.
-#html_logo = None
+# html_logo = None
 
 # The name of an image file (within the static path) to use as favicon of the
 # docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
 # pixels large.
-#html_favicon = None
+# html_favicon = None
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = ['_static']
+html_static_path = ["_static"]
 
 # If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
 # using the given strftime format.
-#html_last_updated_fmt = '%b %d, %Y'
+# html_last_updated_fmt = '%b %d, %Y'
 
 # If true, SmartyPants will be used to convert quotes and dashes to
 # typographically correct entities.
-#html_use_smartypants = True
+# html_use_smartypants = True
 
 # Custom sidebar templates, maps document names to template names.
-#html_sidebars = {}
+# html_sidebars = {}
 
 # Additional templates that should be rendered to pages, maps page names to
 # template names.
-#html_additional_pages = {}
+# html_additional_pages = {}
 
 # If false, no module index is generated.
-#html_use_modindex = True
+# html_use_modindex = True
 
 # If false, no index is generated.
-#html_use_index = True
+# html_use_index = True
 
 # If true, the index is split into individual pages for each letter.
-#html_split_index = False
+# html_split_index = False
 
 # If true, links to the reST sources are added to the pages.
-#html_show_sourcelink = True
+# html_show_sourcelink = True
 
 # If true, an OpenSearch description file will be output, and all pages will
 # contain a <link> tag referring to it.  The value of this option must be the
 # base URL from which the finished HTML is served.
-#html_use_opensearch = ''
+# html_use_opensearch = ''
 
 # If nonempty, this is the file name suffix for HTML files (e.g. ".xhtml").
-#html_file_suffix = ''
+# html_file_suffix = ''
 
 # Output file base name for HTML help builder.
-htmlhelp_basename = 'ploneappdiscussiondoc'
+htmlhelp_basename = "ploneappdiscussiondoc"
 
 
 # -- Options for LaTeX output --------------------------------------------
 
 # The paper size ('letter' or 'a4').
-#latex_paper_size = 'letter'
+# latex_paper_size = 'letter'
 
 # The font size ('10pt', '11pt' or '12pt').
-#latex_font_size = '10pt'
+# latex_font_size = '10pt'
 
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, documentclass [howto/manual]).
 latex_documents = [
-    ('index', 'ploneappdiscussion.tex', u'plone.app.discussion Documentation',
-     u'Timo Stollenwerk', 'manual'),
+    (
+        "index",
+        "ploneappdiscussion.tex",
+        "plone.app.discussion Documentation",
+        "Timo Stollenwerk",
+        "manual",
+    ),
 ]
 
 # The name of an image file (relative to this directory) to place at the top of
 # the title page.
-#latex_logo = None
+# latex_logo = None
 
 # For "manual" documents, if this is true, then toplevel headings are parts,
 # not chapters.
-#latex_use_parts = False
+# latex_use_parts = False
 
 # Additional stuff for the LaTeX preamble.
-#latex_preamble = ''
+# latex_preamble = ''
 
 # Documents to append as an appendix to all manuals.
-#latex_appendices = []
+# latex_appendices = []
 
 # If false, no module index is generated.
-#latex_use_modindex = True
+# latex_use_modindex = True
 
 
 # Example configuration for intersphinx: refer to the Python standard library.
-intersphinx_mapping = {'http://docs.python.org/': None}
+intersphinx_mapping = {"http://docs.python.org/": None}
diff --git a/docs/source/howtos/howto_extend_the_comment_form.txt b/docs/source/howtos/howto_extend_the_comment_form.txt
index 605e0ef..3afaf6a 100644
--- a/docs/source/howtos/howto_extend_the_comment_form.txt
+++ b/docs/source/howtos/howto_extend_the_comment_form.txt
@@ -58,13 +58,13 @@ comment form with the "website" field::
 
     # Interface to define the fields we want to add to the comment form.
     class ICommentExtenderFields(Interface):
-        website = schema.TextLine(title=u"Website", required=False)
+        website = schema.TextLine(title="Website", required=False)
 
     # Persistent class that implements the ICommentExtenderFields interface
     @adapter(Comment)
     class CommentExtenderFields(Persistent):
         interface.implements(ICommentExtenderFields)
-        website = u""
+        website = ""
 
     # CommentExtenderFields factory
     CommentExtenderFactory = factory(CommentExtenderFields)
diff --git a/docs/source/howtos/howto_make_pad_work_with_a_dexterity_content_type.txt b/docs/source/howtos/howto_make_pad_work_with_a_dexterity_content_type.txt
index b134648..84610b3 100644
--- a/docs/source/howtos/howto_make_pad_work_with_a_dexterity_content_type.txt
+++ b/docs/source/howtos/howto_make_pad_work_with_a_dexterity_content_type.txt
@@ -20,8 +20,8 @@ configure.zcml::
 Define an interface IMyDexterityContentType groked schema, I added::
 
         allowDiscussion  = schema.Bool(
-            title=_(u"Allow Users to Comment"),
-            description=_(u"Allow users to commemt on you.  Comments
+            title=_("Allow Users to Comment"),
+            description=_("Allow users to comment on you.  Comments
 are shown at the end of each page"),
             required=True,
             default=True,
diff --git a/news/195.breaking b/news/195.breaking
new file mode 100644
index 0000000..41d8e37
--- /dev/null
+++ b/news/195.breaking
@@ -0,0 +1,2 @@
+Code style black & isort. Remove six usage. Use plone.base and move annotation key over to here.
+[jensens]
diff --git a/plone/__init__.py b/plone/__init__.py
index 68c04af..5284146 100644
--- a/plone/__init__.py
+++ b/plone/__init__.py
@@ -1,2 +1 @@
-# -*- coding: utf-8 -*-
-__import__('pkg_resources').declare_namespace(__name__)
+__import__("pkg_resources").declare_namespace(__name__)
diff --git a/plone/app/__init__.py b/plone/app/__init__.py
index 68c04af..5284146 100644
--- a/plone/app/__init__.py
+++ b/plone/app/__init__.py
@@ -1,2 +1 @@
-# -*- coding: utf-8 -*-
-__import__('pkg_resources').declare_namespace(__name__)
+__import__("pkg_resources").declare_namespace(__name__)
diff --git a/plone/app/discussion/__init__.py b/plone/app/discussion/__init__.py
index 1936adc..8efe8b3 100644
--- a/plone/app/discussion/__init__.py
+++ b/plone/app/discussion/__init__.py
@@ -1,5 +1,4 @@
-# -*- coding: utf-8 -*-
 from zope.i18nmessageid import MessageFactory
 
 
-_ = MessageFactory('plone')
+_ = MessageFactory("plone")
diff --git a/plone/app/discussion/browser/captcha.py b/plone/app/discussion/browser/captcha.py
index 090fce9..7e10d12 100644
--- a/plone/app/discussion/browser/captcha.py
+++ b/plone/app/discussion/browser/captcha.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 # Captcha validator, see captcha.txt for design notes.
 from persistent import Persistent
 from plone.app.discussion.browser.comments import CommentForm
@@ -21,9 +20,9 @@ from zope.publisher.interfaces.browser import IDefaultBrowserLayer
 @adapter(Comment)
 @interface.implementer(ICaptcha)
 class Captcha(Persistent):
-    """Captcha input field.
-    """
-    captcha = u''
+    """Captcha input field."""
+
+    captcha = ""
 
 
 Captcha = factory(Captcha)
@@ -47,22 +46,24 @@ class CaptchaExtender(extensible.FormExtender):
         registry = queryUtility(IRegistry)
         settings = registry.forInterface(IDiscussionSettings, check=False)
         self.captcha = settings.captcha
-        portal_membership = getToolByName(self.context, 'portal_membership')
+        portal_membership = getToolByName(self.context, "portal_membership")
         self.isAnon = portal_membership.isAnonymousUser()
 
     def update(self):
-        if self.captcha != 'disabled' and self.isAnon:
+        if self.captcha != "disabled" and self.isAnon:
             # Add a captcha field if captcha is enabled in the registry
-            self.add(ICaptcha, prefix='')
-            if self.captcha == 'captcha':
+            self.add(ICaptcha, prefix="")
+            if self.captcha == "captcha":
                 from plone.formwidget.captcha import CaptchaFieldWidget
-                self.form.fields['captcha'].widgetFactory = CaptchaFieldWidget
-            elif self.captcha == 'recaptcha':
+
+                self.form.fields["captcha"].widgetFactory = CaptchaFieldWidget
+            elif self.captcha == "recaptcha":
                 from plone.formwidget.recaptcha import ReCaptchaFieldWidget
-                self.form.fields['captcha'].widgetFactory = \
-                    ReCaptchaFieldWidget
-            elif self.captcha == 'norobots':
+
+                self.form.fields["captcha"].widgetFactory = ReCaptchaFieldWidget
+            elif self.captcha == "norobots":
                 from collective.z3cform.norobots import NorobotsFieldWidget
-                self.form.fields['captcha'].widgetFactory = NorobotsFieldWidget
+
+                self.form.fields["captcha"].widgetFactory = NorobotsFieldWidget
             else:
-                self.form.fields['captcha'].mode = interfaces.HIDDEN_MODE
+                self.form.fields["captcha"].mode = interfaces.HIDDEN_MODE
diff --git a/plone/app/discussion/browser/comment.py b/plone/app/discussion/browser/comment.py
index 41beecc..fc95a55 100644
--- a/plone/app/discussion/browser/comment.py
+++ b/plone/app/discussion/browser/comment.py
@@ -1,4 +1,3 @@
-# coding: utf-8
 from .comments import CommentForm
 from AccessControl import getSecurityManager
 from Acquisition import aq_inner
@@ -14,7 +13,6 @@ from zope.component import getMultiAdapter
 from zope.component import getUtility
 from zope.event import notify
 from zope.lifecycleevent import ObjectModifiedEvent
-from .comments import CommentForm
 
 
 class View(BrowserView):
@@ -38,8 +36,7 @@ class View(BrowserView):
         context = aq_inner(self.context)
 
         registry = getUtility(IRegistry)
-        view_action_types = registry.get(
-            'plone.types_use_view_action_in_listings', [])
+        view_action_types = registry.get("plone.types_use_view_action_in_listings", [])
 
         obj = aq_parent(aq_parent(context))
         url = obj.absolute_url()
@@ -50,33 +47,34 @@ class View(BrowserView):
         will redirect right to the binary object, bypassing comments.
         """
         if obj.portal_type in view_action_types:
-            url = '{0}/view'.format(url)
+            url = f"{url}/view"
 
-        self.request.response.redirect('{0}#{1}'.format(url, context.id))
+        self.request.response.redirect(f"{url}#{context.id}")
 
 
 class EditCommentForm(CommentForm):
     """Form to edit an existing comment."""
+
     ignoreContext = True
-    id = 'edit-comment-form'
-    label = _(u'edit_comment_form_title', default=u'Edit comment')
+    id = "edit-comment-form"
+    label = _("edit_comment_form_title", default="Edit comment")
 
     def updateWidgets(self):
-        super(EditCommentForm, self).updateWidgets()
-        self.widgets['text'].value = self.context.text
+        super().updateWidgets()
+        self.widgets["text"].value = self.context.text
         # We have to rename the id, otherwise TinyMCE can't initialize
         # because there are two textareas with the same id.
-        self.widgets['text'].id = 'overlay-comment-text'
+        self.widgets["text"].id = "overlay-comment-text"
 
-    def _redirect(self, target=''):
+    def _redirect(self, target=""):
         if not target:
-            portal_state = getMultiAdapter((self.context, self.request),
-                                           name=u'plone_portal_state')
+            portal_state = getMultiAdapter(
+                (self.context, self.request), name="plone_portal_state"
+            )
             target = portal_state.portal_url()
         self.request.response.redirect(target)
 
-    @button.buttonAndHandler(_(u'label_save',
-                               default=u'Save'), name='comment')
+    @button.buttonAndHandler(_("label_save", default="Save"), name="comment")
     def handleComment(self, action):
 
         # Validate form
@@ -85,32 +83,28 @@ class EditCommentForm(CommentForm):
             return
 
         # Check permissions
-        can_edit = getSecurityManager().checkPermission(
-            'Edit comments',
-            self.context)
-        mtool = getToolByName(self.context, 'portal_membership')
+        can_edit = getSecurityManager().checkPermission("Edit comments", self.context)
+        mtool = getToolByName(self.context, "portal_membership")
         if mtool.isAnonymousUser() or not can_edit:
             return
 
         # Update text
-        self.context.text = data['text']
+        self.context.text = data["text"]
         # Notify that the object has been modified
         notify(ObjectModifiedEvent(self.context))
 
         # Redirect to comment
-        IStatusMessage(self.request).add(_(u'comment_edit_notification',
-                                           default='Comment was edited'),
-                                         type='info')
-        return self._redirect(
-            target=self.action.replace('@@edit-comment', '@@view'))
+        IStatusMessage(self.request).add(
+            _("comment_edit_notification", default="Comment was edited"), type="info"
+        )
+        return self._redirect(target=self.action.replace("@@edit-comment", "@@view"))
 
-    @button.buttonAndHandler(_(u'cancel_form_button',
-                               default=u'Cancel'), name='cancel')
+    @button.buttonAndHandler(_("cancel_form_button", default="Cancel"), name="cancel")
     def handle_cancel(self, action):
         IStatusMessage(self.request).add(
-            _(u'comment_edit_cancel_notification',
-              default=u'Edit comment cancelled'),
-            type='info')
+            _("comment_edit_cancel_notification", default="Edit comment cancelled"),
+            type="info",
+        )
         return self._redirect(target=self.context.absolute_url())
 
 
diff --git a/plone/app/discussion/browser/comments.py b/plone/app/discussion/browser/comments.py
index d8ee95f..387cead 100644
--- a/plone/app/discussion/browser/comments.py
+++ b/plone/app/discussion/browser/comments.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 from AccessControl import getSecurityManager
 from AccessControl import Unauthorized
 from Acquisition import aq_inner
@@ -12,15 +11,15 @@ from plone.app.discussion.interfaces import IConversation
 from plone.app.discussion.interfaces import IDiscussionSettings
 from plone.app.discussion.interfaces import IReplies
 from plone.app.layout.viewlets.common import ViewletBase
+from plone.base.utils import safe_text
 from plone.registry.interfaces import IRegistry
 from plone.z3cform import z2
 from plone.z3cform.fieldsets import extensible
 from plone.z3cform.interfaces import IWrappedForm
 from Products.CMFCore.utils import getToolByName
-from Products.CMFPlone.utils import safe_unicode
 from Products.Five.browser.pagetemplatefile import ViewPageTemplateFile
 from Products.statusmessages.interfaces import IStatusMessage
-from six.moves.urllib.parse import quote
+from urllib.parse import quote
 from z3c.form import button
 from z3c.form import field
 from z3c.form import form
@@ -35,28 +34,28 @@ from zope.interface import alsoProvides
 
 
 COMMENT_DESCRIPTION_PLAIN_TEXT = _(
-    u'comment_description_plain_text',
-    default=u'You can add a comment by filling out the form below. '
-            u'Plain text formatting.',
+    "comment_description_plain_text",
+    default="You can add a comment by filling out the form below. "
+    "Plain text formatting.",
 )
 
 COMMENT_DESCRIPTION_MARKDOWN = _(
-    u'comment_description_markdown',
-    default=u'You can add a comment by filling out the form below. '
-            u'Plain text formatting. You can use the Markdown syntax for '
-            u'links and images.',
+    "comment_description_markdown",
+    default="You can add a comment by filling out the form below. "
+    "Plain text formatting. You can use the Markdown syntax for "
+    "links and images.",
 )
 
 COMMENT_DESCRIPTION_INTELLIGENT_TEXT = _(
-    u'comment_description_intelligent_text',
-    default=u'You can add a comment by filling out the form below. '
-            u'Plain text formatting. Web and email addresses are '
-            u'transformed into clickable links.',
+    "comment_description_intelligent_text",
+    default="You can add a comment by filling out the form below. "
+    "Plain text formatting. Web and email addresses are "
+    "transformed into clickable links.",
 )
 
 COMMENT_DESCRIPTION_MODERATION_ENABLED = _(
-    u'comment_description_moderation_enabled',
-    default=u'Comments are moderated.',
+    "comment_description_moderation_enabled",
+    default="Comments are moderated.",
 )
 
 
@@ -64,30 +63,31 @@ class CommentForm(extensible.ExtensibleForm, form.Form):
 
     ignoreContext = True  # don't use context to get widget data
     id = None
-    label = _(u'Add a comment')
-    fields = field.Fields(IComment).omit('portal_type',
-                                         '__parent__',
-                                         '__name__',
-                                         'comment_id',
-                                         'mime_type',
-                                         'creator',
-                                         'creation_date',
-                                         'modification_date',
-                                         'author_username',
-                                         'title')
+    label = _("Add a comment")
+    fields = field.Fields(IComment).omit(
+        "portal_type",
+        "__parent__",
+        "__name__",
+        "comment_id",
+        "mime_type",
+        "creator",
+        "creation_date",
+        "modification_date",
+        "author_username",
+        "title",
+    )
 
     def updateFields(self):
-        super(CommentForm, self).updateFields()
-        self.fields['user_notification'].widgetFactory = \
-            SingleCheckBoxFieldWidget
+        super().updateFields()
+        self.fields["user_notification"].widgetFactory = SingleCheckBoxFieldWidget
 
     def updateWidgets(self):
-        super(CommentForm, self).updateWidgets()
+        super().updateWidgets()
 
         # Widgets
-        self.widgets['in_reply_to'].mode = interfaces.HIDDEN_MODE
-        self.widgets['text'].addClass('autoresize')
-        self.widgets['user_notification'].label = _(u'')
+        self.widgets["in_reply_to"].mode = interfaces.HIDDEN_MODE
+        self.widgets["text"].addClass("autoresize")
+        self.widgets["user_notification"].label = _("")
         # Reset widget field settings to their defaults, which may be changed
         # further on.  Otherwise, the email field might get set to required
         # when an anonymous user visits, and then remain required when an
@@ -97,19 +97,19 @@ class CommentForm(extensible.ExtensibleForm, form.Form):
         # would have no effect until the instance was restarted.  Note that the
         # widget is new each time, but the field is the same item in memory as
         # the previous time.
-        self.widgets['author_email'].field.required = False
+        self.widgets["author_email"].field.required = False
         # The widget is new, but its 'required' setting is based on the
         # previous value on the field, so we need to reset it here.  Changing
         # the field in updateFields does not help.
-        self.widgets['author_email'].required = False
+        self.widgets["author_email"].required = False
 
         # Rename the id of the text widgets because there can be css-id
         # clashes with the text field of documents when using and overlay
         # with TinyMCE.
-        self.widgets['text'].id = 'form-widgets-comment-text'
+        self.widgets["text"].id = "form-widgets-comment-text"
 
         # Anonymous / Logged-in
-        mtool = getToolByName(self.context, 'portal_membership')
+        mtool = getToolByName(self.context, "portal_membership")
         anon = mtool.isAnonymousUser()
 
         registry = queryUtility(IRegistry)
@@ -119,56 +119,55 @@ class CommentForm(extensible.ExtensibleForm, form.Form):
             if settings.anonymous_email_enabled:
                 # according to IDiscussionSettings.anonymous_email_enabled:
                 # 'If selected, anonymous user will have to give their email.'
-                self.widgets['author_email'].field.required = True
-                self.widgets['author_email'].required = True
+                self.widgets["author_email"].field.required = True
+                self.widgets["author_email"].required = True
             else:
-                self.widgets['author_email'].mode = interfaces.HIDDEN_MODE
+                self.widgets["author_email"].mode = interfaces.HIDDEN_MODE
         else:
-            self.widgets['author_name'].mode = interfaces.HIDDEN_MODE
-            self.widgets['author_email'].mode = interfaces.HIDDEN_MODE
+            self.widgets["author_name"].mode = interfaces.HIDDEN_MODE
+            self.widgets["author_email"].mode = interfaces.HIDDEN_MODE
 
         member = mtool.getAuthenticatedMember()
-        member_email = member.getProperty('email')
+        member_email = member.getProperty("email")
 
         # Hide the user_notification checkbox if user notification is disabled
         # or the user is not logged in. Also check if the user has a valid
         # email address
-        member_email_is_empty = member_email == ''
+        member_email_is_empty = member_email == ""
         user_notification_disabled = not settings.user_notification_enabled
         if member_email_is_empty or user_notification_disabled or anon:
-            self.widgets['user_notification'].mode = interfaces.HIDDEN_MODE
+            self.widgets["user_notification"].mode = interfaces.HIDDEN_MODE
 
     def updateActions(self):
-        super(CommentForm, self).updateActions()
-        self.actions['cancel'].addClass('btn btn-secondary')
-        self.actions['cancel'].addClass('hide')
-        self.actions['comment'].addClass('btn btn-primary')
+        super().updateActions()
+        self.actions["cancel"].addClass("btn btn-secondary")
+        self.actions["cancel"].addClass("hide")
+        self.actions["comment"].addClass("btn btn-primary")
 
     def get_author(self, data):
         context = aq_inner(self.context)
         # some attributes are not always set
-        author_name = u''
+        author_name = ""
 
         # Make sure author_name/ author_email is properly encoded
-        if 'author_name' in data:
-            author_name = safe_unicode(data['author_name'])
-        if 'author_email' in data:
-            author_email = safe_unicode(data['author_email'])
+        if "author_name" in data:
+            author_name = safe_text(data["author_name"])
+        if "author_email" in data:
+            author_email = safe_text(data["author_email"])
 
         # Set comment author properties for anonymous users or members
-        portal_membership = getToolByName(context, 'portal_membership')
+        portal_membership = getToolByName(context, "portal_membership")
         anon = portal_membership.isAnonymousUser()
-        if not anon and getSecurityManager().checkPermission(
-                'Reply to item', context):
+        if not anon and getSecurityManager().checkPermission("Reply to item", context):
             # Member
             member = portal_membership.getAuthenticatedMember()
-            email = safe_unicode(member.getProperty('email'))
-            fullname = member.getProperty('fullname')
-            if not fullname or fullname == '':
+            email = safe_text(member.getProperty("email"))
+            fullname = member.getProperty("fullname")
+            if not fullname or fullname == "":
                 fullname = member.getUserName()
-            fullname = safe_unicode(fullname)
+            fullname = safe_text(fullname)
             author_name = fullname
-            email = safe_unicode(email)
+            email = safe_text(email)
             # XXX: according to IComment interface author_email must not be  # noqa T000
             # set for logged in users, cite:
             # 'for anonymous comments only, set to None for logged in comments'
@@ -179,7 +178,7 @@ class CommentForm(extensible.ExtensibleForm, form.Form):
 
     def create_comment(self, data):
         context = aq_inner(self.context)
-        comment = createObject('plone.Comment')
+        comment = createObject("plone.Comment")
 
         registry = queryUtility(IRegistry)
         settings = registry.forInterface(IDiscussionSettings, check=False)
@@ -200,42 +199,42 @@ class CommentForm(extensible.ExtensibleForm, form.Form):
         comment.author_name, comment.author_email = self.get_author(data)
 
         # Set comment author properties for anonymous users or members
-        portal_membership = getToolByName(context, 'portal_membership')
+        portal_membership = getToolByName(context, "portal_membership")
         anon = portal_membership.isAnonymousUser()
         if anon and anonymous_comments:
             # Anonymous Users
             comment.user_notification = None
         elif not anon and getSecurityManager().checkPermission(
-                'Reply to item', context):
+            "Reply to item", context
+        ):
             # Member
             member = portal_membership.getAuthenticatedMember()
             memberid = member.getId()
             user = member.getUser()
             comment.changeOwnership(user, recursive=False)
-            comment.manage_setLocalRoles(memberid, ['Owner'])
+            comment.manage_setLocalRoles(memberid, ["Owner"])
             comment.creator = memberid
             comment.author_username = memberid
 
         else:  # pragma: no cover
             raise Unauthorized(
-                u'Anonymous user tries to post a comment, but anonymous '
-                u'commenting is disabled. Or user does not have the '
-                u"'reply to item' permission.",
+                "Anonymous user tries to post a comment, but anonymous "
+                "commenting is disabled. Or user does not have the "
+                "'reply to item' permission.",
             )
 
         return comment
 
-    @button.buttonAndHandler(_(u'add_comment_button', default=u'Comment'),
-                             name='comment')
+    @button.buttonAndHandler(_("add_comment_button", default="Comment"), name="comment")
     def handleComment(self, action):
         context = aq_inner(self.context)
 
         # Check if conversation is enabled on this content object
         if not self.__parent__.restrictedTraverse(
-            '@@conversation_view',
+            "@@conversation_view",
         ).enabled():
             raise Unauthorized(
-                'Discussion is not enabled for this content object.',
+                "Discussion is not enabled for this content object.",
             )
 
         # Validation form
@@ -246,28 +245,26 @@ class CommentForm(extensible.ExtensibleForm, form.Form):
         # Validate Captcha
         registry = queryUtility(IRegistry)
         settings = registry.forInterface(IDiscussionSettings, check=False)
-        portal_membership = getToolByName(self.context, 'portal_membership')
-        captcha_enabled = settings.captcha != 'disabled'
+        portal_membership = getToolByName(self.context, "portal_membership")
+        captcha_enabled = settings.captcha != "disabled"
         anonymous_comments = settings.anonymous_comments
         anon = portal_membership.isAnonymousUser()
         if captcha_enabled and anonymous_comments and anon:
-            if 'captcha' not in data:
-                data['captcha'] = u''
-            captcha = CaptchaValidator(self.context,
-                                       self.request,
-                                       None,
-                                       ICaptcha['captcha'],
-                                       None)
-            captcha.validate(data['captcha'])
+            if "captcha" not in data:
+                data["captcha"] = ""
+            captcha = CaptchaValidator(
+                self.context, self.request, None, ICaptcha["captcha"], None
+            )
+            captcha.validate(data["captcha"])
 
         # Create comment
         comment = self.create_comment(data)
 
         # Add comment to conversation
         conversation = IConversation(self.__parent__)
-        if data['in_reply_to']:
+        if data["in_reply_to"]:
             # Add a reply to an existing comment
-            conversation_to_reply_to = conversation.get(data['in_reply_to'])
+            conversation_to_reply_to = conversation.get(data["in_reply_to"])
             replies = IReplies(conversation_to_reply_to)
             comment_id = replies.addComment(comment)
         else:
@@ -279,25 +276,24 @@ class CommentForm(extensible.ExtensibleForm, form.Form):
         # shown to the user that his/her comment awaits moderation. If the user
         # has 'review comments' permission, he/she is redirected directly
         # to the comment.
-        can_review = getSecurityManager().checkPermission('Review comments',
-                                                          context)
-        workflowTool = getToolByName(context, 'portal_workflow')
+        can_review = getSecurityManager().checkPermission("Review comments", context)
+        workflowTool = getToolByName(context, "portal_workflow")
         comment_review_state = workflowTool.getInfoFor(
             comment,
-            'review_state',
+            "review_state",
             None,
         )
-        if comment_review_state == 'pending' and not can_review:
+        if comment_review_state == "pending" and not can_review:
             # Show info message when comment moderation is enabled
             IStatusMessage(self.context.REQUEST).addStatusMessage(
-                _('Your comment awaits moderator approval.'),
-                type='info')
+                _("Your comment awaits moderator approval."), type="info"
+            )
             self.request.response.redirect(self.action)
         else:
             # Redirect to comment (inside a content object page)
-            self.request.response.redirect(self.action + '#' + str(comment_id))
+            self.request.response.redirect(self.action + "#" + str(comment_id))
 
-    @button.buttonAndHandler(_(u'Cancel'))
+    @button.buttonAndHandler(_("Cancel"))
     def handleCancel(self, action):
         # This method should never be called, it's only there to show
         # a cancel button that is handled by a jQuery method.
@@ -307,15 +303,15 @@ class CommentForm(extensible.ExtensibleForm, form.Form):
 class CommentsViewlet(ViewletBase):
 
     form = CommentForm
-    index = ViewPageTemplateFile('comments.pt')
+    index = ViewPageTemplateFile("comments.pt")
 
     def update(self):
-        super(CommentsViewlet, self).update()
+        super().update()
         discussion_allowed = self.is_discussion_allowed()
         anonymous_allowed_or_can_reply = (
-            self.is_anonymous() and
-            self.anonymous_discussion_allowed() or
-            self.can_reply()
+            self.is_anonymous()
+            and self.anonymous_discussion_allowed()
+            or self.can_reply()
         )
         if discussion_allowed and anonymous_allowed_or_can_reply:
             z2.switch_on(self, request_layer=IFormLayer)
@@ -326,30 +322,29 @@ class CommentsViewlet(ViewletBase):
     # view methods
 
     def can_reply(self):
-        """Returns true if current user has the 'Reply to item' permission.
-        """
-        return getSecurityManager().checkPermission('Reply to item',
-                                                    aq_inner(self.context))
+        """Returns true if current user has the 'Reply to item' permission."""
+        return getSecurityManager().checkPermission(
+            "Reply to item", aq_inner(self.context)
+        )
 
     def can_manage(self):
         """We keep this method for <= 1.0b9 backward compatibility. Since we do
-           not want any API changes in beta releases.
+        not want any API changes in beta releases.
         """
         return self.can_review()
 
     def can_review(self):
-        """Returns true if current user has the 'Review comments' permission.
-        """
-        return getSecurityManager().checkPermission('Review comments',
-                                                    aq_inner(self.context))
+        """Returns true if current user has the 'Review comments' permission."""
+        return getSecurityManager().checkPermission(
+            "Review comments", aq_inner(self.context)
+        )
 
     def can_delete_own(self, comment):
         """Returns true if the current user can delete the comment. Only
         comments without replies can be deleted.
         """
         try:
-            return comment.restrictedTraverse(
-                '@@delete-own-comment').can_delete()
+            return comment.restrictedTraverse("@@delete-own-comment").can_delete()
         except Unauthorized:
             return False
 
@@ -358,8 +353,7 @@ class CommentsViewlet(ViewletBase):
         no replies. This is used to prepare hidden form buttons for JS.
         """
         try:
-            return comment.restrictedTraverse(
-                '@@delete-own-comment').could_delete()
+            return comment.restrictedTraverse("@@delete-own-comment").could_delete()
         except Unauthorized:
             return False
 
@@ -367,58 +361,63 @@ class CommentsViewlet(ViewletBase):
         """Returns true if current user has the 'Edit comments'
         permission.
         """
-        return getSecurityManager().checkPermission('Edit comments',
-                                                    aq_inner(reply))
+        return getSecurityManager().checkPermission("Edit comments", aq_inner(reply))
 
     def can_delete(self, reply):
         """Returns true if current user has the 'Delete comments'
         permission.
         """
-        return getSecurityManager().checkPermission('Delete comments',
-                                                    aq_inner(reply))
+        return getSecurityManager().checkPermission("Delete comments", aq_inner(reply))
 
     def is_discussion_allowed(self):
         context = aq_inner(self.context)
-        return context.restrictedTraverse('@@conversation_view').enabled()
+        return context.restrictedTraverse("@@conversation_view").enabled()
 
     def comment_transform_message(self):
         """Returns the description that shows up above the comment text,
-           dependent on the text_transform setting and the comment moderation
-           workflow in the discussion control panel.
+        dependent on the text_transform setting and the comment moderation
+        workflow in the discussion control panel.
         """
         context = aq_inner(self.context)
         registry = queryUtility(IRegistry)
         settings = registry.forInterface(IDiscussionSettings, check=False)
 
         # text transform setting
-        if settings.text_transform == 'text/x-web-intelligent':
-            message = translate(Message(COMMENT_DESCRIPTION_INTELLIGENT_TEXT),
-                                context=self.request)
-        elif settings.text_transform == 'text/x-web-markdown':
-            message = translate(Message(COMMENT_DESCRIPTION_MARKDOWN),
-                                context=self.request)
+        if settings.text_transform == "text/x-web-intelligent":
+            message = translate(
+                Message(COMMENT_DESCRIPTION_INTELLIGENT_TEXT), context=self.request
+            )
+        elif settings.text_transform == "text/x-web-markdown":
+            message = translate(
+                Message(COMMENT_DESCRIPTION_MARKDOWN), context=self.request
+            )
         else:
-            message = translate(Message(COMMENT_DESCRIPTION_PLAIN_TEXT),
-                                context=self.request)
+            message = translate(
+                Message(COMMENT_DESCRIPTION_PLAIN_TEXT), context=self.request
+            )
 
         # comment workflow
-        wftool = getToolByName(context, 'portal_workflow', None)
-        workflow_chain = wftool.getChainForPortalType('Discussion Item')
+        wftool = getToolByName(context, "portal_workflow", None)
+        workflow_chain = wftool.getChainForPortalType("Discussion Item")
         if workflow_chain:
             comment_workflow = workflow_chain[0]
             comment_workflow = wftool[comment_workflow]
             # check if the current workflow implements a pending state. If this
             # is true comments are moderated
-            if 'pending' in comment_workflow.states:
-                message = message + ' ' + \
-                    translate(Message(COMMENT_DESCRIPTION_MODERATION_ENABLED),
-                              context=self.request)
+            if "pending" in comment_workflow.states:
+                message = (
+                    message
+                    + " "
+                    + translate(
+                        Message(COMMENT_DESCRIPTION_MODERATION_ENABLED),
+                        context=self.request,
+                    )
+                )
 
         return message
 
     def has_replies(self, workflow_actions=False):
-        """Returns true if there are replies.
-        """
+        """Returns true if there are replies."""
         if self.get_replies(workflow_actions) is not None:
             try:
                 next(self.get_replies(workflow_actions))
@@ -442,31 +441,32 @@ class CommentsViewlet(ViewletBase):
         if conversation is None:
             return iter([])
 
-        wf = getToolByName(context, 'portal_workflow')
+        wf = getToolByName(context, "portal_workflow")
         # workflow_actions is only true when user
         # has 'Manage portal' permission
 
         def replies_with_workflow_actions():
             # Generator that returns replies dict with workflow actions
             for r in conversation.getThreads():
-                comment_obj = r['comment']
+                comment_obj = r["comment"]
                 # list all possible workflow actions
                 actions = [
-                    a for a in wf.listActionInfos(object=comment_obj)
-                    if a['category'] == 'workflow' and a['allowed']
+                    a
+                    for a in wf.listActionInfos(object=comment_obj)
+                    if a["category"] == "workflow" and a["allowed"]
                 ]
                 r = r.copy()
-                r['actions'] = actions
+                r["actions"] = actions
                 yield r
 
         def published_replies():
             # Generator that returns replies dict with workflow status.
             for r in conversation.getThreads():
-                comment_obj = r['comment']
-                workflow_status = wf.getInfoFor(comment_obj, 'review_state')
-                if workflow_status == 'published':
+                comment_obj = r["comment"]
+                workflow_status = wf.getInfoFor(comment_obj, "review_state")
+                if workflow_status == "published":
                     r = r.copy()
-                    r['workflow_status'] = workflow_status
+                    r["workflow_status"] = workflow_status
                     yield r
 
         # Return all direct replies
@@ -480,20 +480,16 @@ class CommentsViewlet(ViewletBase):
         if username is None:
             return None
         else:
-            return '{0}/author/{1}'.format(self.context.portal_url(), username)
+            return f"{self.context.portal_url()}/author/{username}"
 
     def get_commenter_portrait(self, username=None):
 
         if username is None:
             # return the default user image if no username is given
-            return 'defaultUser.png'
+            return "defaultUser.png"
         else:
-            portal_membership = getToolByName(self.context,
-                                              'portal_membership',
-                                              None)
-            return portal_membership\
-                .getPersonalPortrait(username)\
-                .absolute_url()
+            portal_membership = getToolByName(self.context, "portal_membership", None)
+            return portal_membership.getPersonalPortrait(username).absolute_url()
 
     def anonymous_discussion_allowed(self):
         # Check if anonymous comments are allowed in the registry
@@ -520,20 +516,18 @@ class CommentsViewlet(ViewletBase):
         return settings.show_commenter_image
 
     def is_anonymous(self):
-        portal_membership = getToolByName(self.context,
-                                          'portal_membership',
-                                          None)
+        portal_membership = getToolByName(self.context, "portal_membership", None)
         return portal_membership.isAnonymousUser()
 
     def login_action(self):
-        return '{0}/login_form?came_from={1}'.format(
+        return "{}/login_form?came_from={}".format(
             self.navigation_root_url,
-            quote(self.request.get('URL', '')),
+            quote(self.request.get("URL", "")),
         )
 
     def format_time(self, time):
         # We have to transform Python datetime into Zope DateTime
         # before we can call toLocalizedTime.
-        util = getToolByName(self.context, 'translation_service')
+        util = getToolByName(self.context, "translation_service")
         zope_time = DateTime(time.isoformat())
         return util.toLocalizedTime(zope_time, long_format=True)
diff --git a/plone/app/discussion/browser/configure.zcml b/plone/app/discussion/browser/configure.zcml
index 63f80a4..0892259 100644
--- a/plone/app/discussion/browser/configure.zcml
+++ b/plone/app/discussion/browser/configure.zcml
@@ -48,7 +48,7 @@
 
     <!-- Moderate comments enabled view -->
     <browser:page
-        for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+        for="plone.base.interfaces.IPloneSiteRoot"
         name="moderate-comments-enabled"
         layer="..interfaces.IDiscussionLayer"
         class=".moderation.ModerateCommentsEnabled"
@@ -141,14 +141,14 @@
     <!-- Control panel -->
     <browser:page
         name="discussion-controlpanel"
-        for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+        for="plone.base.interfaces.IPloneSiteRoot"
         class=".controlpanel.DiscussionSettingsControlPanel"
         permission="cmf.ManagePortal"
         />
     <!-- Deprecated controlpanel url -->
     <browser:page
         name="discussion-settings"
-        for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+        for="plone.base.interfaces.IPloneSiteRoot"
         class=".controlpanel.DiscussionSettingsControlPanel"
         permission="cmf.ManagePortal"
         />
diff --git a/plone/app/discussion/browser/controlpanel.py b/plone/app/discussion/browser/controlpanel.py
index 272fbb0..b9a3e23 100644
--- a/plone/app/discussion/browser/controlpanel.py
+++ b/plone/app/discussion/browser/controlpanel.py
@@ -1,12 +1,12 @@
-# -*- coding: utf-8 -*-
-from plone.app.discussion.interfaces import _
-from plone.app.discussion.interfaces import IDiscussionSettings
-from plone.app.discussion.upgrades import update_registry
+from ..interfaces import _
+from ..interfaces import IDiscussionSettings
+from ..upgrades import update_registry
 from plone.app.registry.browser import controlpanel
+from plone.base.interfaces.controlpanel import IConfigurationChangedEvent
+from plone.base.interfaces.controlpanel import IMailSchema
 from plone.registry.interfaces import IRecordModifiedEvent
 from plone.registry.interfaces import IRegistry
 from Products.CMFCore.utils import getToolByName
-from Products.CMFPlone.interfaces.controlpanel import IMailSchema
 from Products.Five.browser.pagetemplatefile import ViewPageTemplateFile
 from Products.statusmessages.interfaces import IStatusMessage
 from z3c.form import button
@@ -16,87 +16,76 @@ from zope.component import getUtility
 from zope.component import queryUtility
 from zope.component.hooks import getSite
 
-# try/except was added because Configuration Changed Event was moved inside the
-# controlpanel file in the PR #2495 on Products.CMFPlone
-try:
-    from Products.CMFPlone.interfaces.controlpanel import IConfigurationChangedEvent  # noqa: E501
-except ImportError:
-    from Products.CMFPlone.interfaces import IConfigurationChangedEvent
-
 
 class DiscussionSettingsEditForm(controlpanel.RegistryEditForm):
-    """Discussion settings form.
-    """
+    """Discussion settings form."""
+
     schema = IDiscussionSettings
-    id = 'DiscussionSettingsEditForm'
-    label = _(u'Discussion settings')
+    id = "DiscussionSettingsEditForm"
+    label = _("Discussion settings")
     description = _(
-        u'help_discussion_settings_editform',
-        default=u'Some discussion related settings are not '
-                u'located in the Discussion Control Panel.\n'
-                u'To enable comments for a specific content type, '
-                u'go to the Types Control Panel of this type and '
-                u'choose "Allow comments".\n'
-                u'To enable the moderation workflow for comments, '
-                u'go to the Types Control Panel, choose '
-                u'"Comment" and set workflow to '
-                u'"Comment Review Workflow".',
+        "help_discussion_settings_editform",
+        default="Some discussion related settings are not "
+        "located in the Discussion Control Panel.\n"
+        "To enable comments for a specific content type, "
+        "go to the Types Control Panel of this type and "
+        'choose "Allow comments".\n'
+        "To enable the moderation workflow for comments, "
+        "go to the Types Control Panel, choose "
+        '"Comment" and set workflow to '
+        '"Comment Review Workflow".',
     )
 
     def updateFields(self):
-        super(DiscussionSettingsEditForm, self).updateFields()
-        self.fields['globally_enabled'].widgetFactory = \
-            SingleCheckBoxFieldWidget
-        self.fields['moderation_enabled'].widgetFactory = \
-            SingleCheckBoxFieldWidget
-        self.fields['edit_comment_enabled'].widgetFactory = \
-            SingleCheckBoxFieldWidget
-        self.fields['delete_own_comment_enabled'].widgetFactory = \
-            SingleCheckBoxFieldWidget
-        self.fields['anonymous_comments'].widgetFactory = \
-            SingleCheckBoxFieldWidget
-        self.fields['show_commenter_image'].widgetFactory = \
-            SingleCheckBoxFieldWidget
-        self.fields['moderator_notification_enabled'].widgetFactory = \
-            SingleCheckBoxFieldWidget
-        self.fields['user_notification_enabled'].widgetFactory = \
-            SingleCheckBoxFieldWidget
+        super().updateFields()
+        self.fields["globally_enabled"].widgetFactory = SingleCheckBoxFieldWidget
+        self.fields["moderation_enabled"].widgetFactory = SingleCheckBoxFieldWidget
+        self.fields["edit_comment_enabled"].widgetFactory = SingleCheckBoxFieldWidget
+        self.fields[
+            "delete_own_comment_enabled"
+        ].widgetFactory = SingleCheckBoxFieldWidget
+        self.fields["anonymous_comments"].widgetFactory = SingleCheckBoxFieldWidget
+        self.fields["show_commenter_image"].widgetFactory = SingleCheckBoxFieldWidget
+        self.fields[
+            "moderator_notification_enabled"
+        ].widgetFactory = SingleCheckBoxFieldWidget
+        self.fields[
+            "user_notification_enabled"
+        ].widgetFactory = SingleCheckBoxFieldWidget
 
     def updateWidgets(self):
         try:
-            super(DiscussionSettingsEditForm, self).updateWidgets()
+            super().updateWidgets()
         except KeyError:
             # upgrade profile not visible in prefs_install_products_form
             # provide auto-upgrade
             update_registry(self.context)
-            super(DiscussionSettingsEditForm, self).updateWidgets()
-        self.widgets['globally_enabled'].label = _(u'Enable Comments')
-        self.widgets['anonymous_comments'].label = _(u'Anonymous Comments')
-        self.widgets['show_commenter_image'].label = _(u'Commenter Image')
-        self.widgets['moderator_notification_enabled'].label = _(
-            u'Moderator Email Notification',
+            super().updateWidgets()
+        self.widgets["globally_enabled"].label = _("Enable Comments")
+        self.widgets["anonymous_comments"].label = _("Anonymous Comments")
+        self.widgets["show_commenter_image"].label = _("Commenter Image")
+        self.widgets["moderator_notification_enabled"].label = _(
+            "Moderator Email Notification",
         )
-        self.widgets['user_notification_enabled'].label = _(
-            u'User Email Notification',
+        self.widgets["user_notification_enabled"].label = _(
+            "User Email Notification",
         )
 
-    @button.buttonAndHandler(_('Save'), name=None)
+    @button.buttonAndHandler(_("Save"), name=None)
     def handleSave(self, action):
         data, errors = self.extractData()
         if errors:
             self.status = self.formErrorsMessage
             return
         self.applyChanges(data)
-        IStatusMessage(self.request).addStatusMessage(_(u'Changes saved'),
-                                                      'info')
-        self.context.REQUEST.RESPONSE.redirect('@@discussion-controlpanel')
+        IStatusMessage(self.request).addStatusMessage(_("Changes saved"), "info")
+        self.context.REQUEST.RESPONSE.redirect("@@discussion-controlpanel")
 
-    @button.buttonAndHandler(_('Cancel'), name='cancel')
+    @button.buttonAndHandler(_("Cancel"), name="cancel")
     def handleCancel(self, action):
-        IStatusMessage(self.request).addStatusMessage(_(u'Edit cancelled'),
-                                                      'info')
+        IStatusMessage(self.request).addStatusMessage(_("Edit cancelled"), "info")
         self.request.response.redirect(
-            '{0}/{1}'.format(
+            "{}/{}".format(
                 self.context.absolute_url(),
                 self.control_panel_view,
             ),
@@ -104,15 +93,15 @@ class DiscussionSettingsEditForm(controlpanel.RegistryEditForm):
 
 
 class DiscussionSettingsControlPanel(controlpanel.ControlPanelFormWrapper):
-    """Discussion settings control panel.
-    """
+    """Discussion settings control panel."""
+
     form = DiscussionSettingsEditForm
-    index = ViewPageTemplateFile('controlpanel.pt')
+    index = ViewPageTemplateFile("controlpanel.pt")
 
     def __call__(self):
         self.mailhost_warning()
         self.custom_comment_workflow_warning()
-        return super(DiscussionSettingsControlPanel, self).__call__()
+        return super().__call__()
 
     @property
     def site_url(self):
@@ -123,43 +112,44 @@ class DiscussionSettingsControlPanel(controlpanel.ControlPanelFormWrapper):
 
     def settings(self):
         """Compose a string that contains all registry settings that are
-           needed for the discussion control panel.
+        needed for the discussion control panel.
         """
         registry = queryUtility(IRegistry)
         settings = registry.forInterface(IDiscussionSettings, check=False)
-        wftool = getToolByName(self.context, 'portal_workflow', None)
-        workflow_chain = wftool.getChainForPortalType('Discussion Item')
+        wftool = getToolByName(self.context, "portal_workflow", None)
+        workflow_chain = wftool.getChainForPortalType("Discussion Item")
         output = []
 
         # Globally enabled
         if settings.globally_enabled:
-            output.append('globally_enabled')
+            output.append("globally_enabled")
 
         # Comment moderation
-        one_state_worklow_disabled = \
-            'comment_one_state_workflow' not in workflow_chain
-        comment_review_workflow_disabled = \
-            'comment_review_workflow' not in workflow_chain
+        one_state_worklow_disabled = "comment_one_state_workflow" not in workflow_chain
+        comment_review_workflow_disabled = (
+            "comment_review_workflow" not in workflow_chain
+        )
         if one_state_worklow_disabled and comment_review_workflow_disabled:
-            output.append('moderation_custom')
+            output.append("moderation_custom")
         elif settings.moderation_enabled:
-            output.append('moderation_enabled')
+            output.append("moderation_enabled")
 
         if settings.edit_comment_enabled:
-            output.append('edit_comment_enabled')
+            output.append("edit_comment_enabled")
 
         if settings.delete_own_comment_enabled:
-            output.append('delete_own_comment_enabled')
+            output.append("delete_own_comment_enabled")
 
         # Anonymous comments
         if settings.anonymous_comments:
-            output.append('anonymous_comments')
+            output.append("anonymous_comments")
 
         # Invalid mail setting
-        ctrlOverview = getMultiAdapter((self.context, self.request),
-                                       name='overview-controlpanel')
+        ctrlOverview = getMultiAdapter(
+            (self.context, self.request), name="overview-controlpanel"
+        )
         if ctrlOverview.mailhost_warning():
-            output.append('invalid_mail_setup')
+            output.append("invalid_mail_setup")
 
         # Workflow
         if workflow_chain:
@@ -167,69 +157,71 @@ class DiscussionSettingsControlPanel(controlpanel.ControlPanelFormWrapper):
             output.append(discussion_workflow)
 
         # Merge all settings into one string
-        return ' '.join(output)
+        return " ".join(output)
 
     def mailhost_warning(self):
-        """Returns true if mailhost is not configured properly.
-        """
+        """Returns true if mailhost is not configured properly."""
         # Copied from Products.CMFPlone/controlpanel/browser/overview.py
         registry = getUtility(IRegistry)
-        mail_settings = registry.forInterface(IMailSchema, prefix='plone')
+        mail_settings = registry.forInterface(IMailSchema, prefix="plone")
         mailhost = mail_settings.smtp_host
         email = mail_settings.email_from_address
         if mailhost and email:
             pass
         else:
-            message = _(u'discussion_text_no_mailhost_configured',
-                default=u'You have not configured a mail host or a site \'From\' address, various features including contact forms, email notification and password reset will not work. Go to the E-Mail Settings to fix this.')  # noqa: E501
-            IStatusMessage(self.request).addStatusMessage(message, 'warning')
+            message = _(
+                "discussion_text_no_mailhost_configured",
+                default="You have not configured a mail host or a site 'From' address, various features including contact forms, email notification and password reset will not work. Go to the E-Mail Settings to fix this.",
+            )  # noqa: E501
+            IStatusMessage(self.request).addStatusMessage(message, "warning")
 
     def custom_comment_workflow_warning(self):
         """Return True if a custom comment workflow is enabled."""
-        wftool = getToolByName(self.context, 'portal_workflow', None)
-        workflow_chain = wftool.getChainForPortalType('Discussion Item')
-        one_state_workflow_enabled = \
-            'comment_one_state_workflow' in workflow_chain
-        comment_review_workflow_enabled = \
-            'comment_review_workflow' in workflow_chain
+        wftool = getToolByName(self.context, "portal_workflow", None)
+        workflow_chain = wftool.getChainForPortalType("Discussion Item")
+        one_state_workflow_enabled = "comment_one_state_workflow" in workflow_chain
+        comment_review_workflow_enabled = "comment_review_workflow" in workflow_chain
         if one_state_workflow_enabled or comment_review_workflow_enabled:
             pass
         else:
-            message = _(u'discussion_text_custom_comment_workflow',
-                default=u'You have configured a custom workflow for the \'Discussion Item\' content type. You can enable/disable the comment moderation in this control panel only if you use one of the default \'Discussion Item\' workflows. Go to the Types control panel to choose a workflow for the \'Discussion Item\' type.')  # noqa: E501
-            IStatusMessage(self.request).addStatusMessage(message, 'warning')
+            message = _(
+                "discussion_text_custom_comment_workflow",
+                default="You have configured a custom workflow for the 'Discussion Item' content type. You can enable/disable the comment moderation in this control panel only if you use one of the default 'Discussion Item' workflows. Go to the Types control panel to choose a workflow for the 'Discussion Item' type.",
+            )  # noqa: E501
+            IStatusMessage(self.request).addStatusMessage(message, "warning")
 
 
 def notify_configuration_changed(event):
-    """Event subscriber that is called every time the configuration changed.
-    """
+    """Event subscriber that is called every time the configuration changed."""
     portal = getSite()
-    wftool = getToolByName(portal, 'portal_workflow', None)
+    wftool = getToolByName(portal, "portal_workflow", None)
 
     if IRecordModifiedEvent.providedBy(event):
         # Discussion control panel setting changed
-        if event.record.fieldName == 'moderation_enabled':
+        if event.record.fieldName == "moderation_enabled":
             # Moderation enabled has changed
             if event.record.value is True:
                 # Enable moderation workflow
-                wftool.setChainForPortalTypes(('Discussion Item',),
-                                              'comment_review_workflow')
+                wftool.setChainForPortalTypes(
+                    ("Discussion Item",), "comment_review_workflow"
+                )
             else:
                 # Disable moderation workflow
-                wftool.setChainForPortalTypes(('Discussion Item',),
-                                              'comment_one_state_workflow')
+                wftool.setChainForPortalTypes(
+                    ("Discussion Item",), "comment_one_state_workflow"
+                )
 
     if IConfigurationChangedEvent.providedBy(event):
         # Types control panel setting changed
-        if 'workflow' in event.data:
+        if "workflow" in event.data:
             registry = queryUtility(IRegistry)
             settings = registry.forInterface(IDiscussionSettings, check=False)
-            workflow_chain = wftool.getChainForPortalType('Discussion Item')
+            workflow_chain = wftool.getChainForPortalType("Discussion Item")
             if workflow_chain:
                 workflow = workflow_chain[0]
-                if workflow == 'comment_one_state_workflow':
+                if workflow == "comment_one_state_workflow":
                     settings.moderation_enabled = False
-                elif workflow == 'comment_review_workflow':
+                elif workflow == "comment_review_workflow":
                     settings.moderation_enabled = True
                 else:
                     # Custom workflow
diff --git a/plone/app/discussion/browser/conversation.py b/plone/app/discussion/browser/conversation.py
index 0017da4..ac0c932 100644
--- a/plone/app/discussion/browser/conversation.py
+++ b/plone/app/discussion/browser/conversation.py
@@ -1,19 +1,19 @@
-# -*- coding: utf-8 -*-
+from ..interfaces import IDiscussionSettings
 from Acquisition import aq_base
 from Acquisition import aq_chain
 from Acquisition import aq_inner
-from plone.app.discussion.interfaces import IDiscussionSettings
+from plone.base.interfaces import INonStructuralFolder
+from plone.base.interfaces import IPloneSiteRoot
+from plone.base.utils import safe_hasattr
 from plone.registry.interfaces import IRegistry
 from Products.CMFCore.interfaces import IFolderish
 from Products.CMFCore.utils import getToolByName
-from Products.CMFPlone.interfaces import INonStructuralFolder
-from Products.CMFPlone.interfaces import IPloneSiteRoot
-from Products.CMFPlone.utils import safe_hasattr
 from zope.component import queryUtility
 
 
 try:
     from plone.dexterity.interfaces import IDexterityContent
+
     DEXTERITY_INSTALLED = True
 except ImportError:
     DEXTERITY_INSTALLED = False
@@ -26,15 +26,14 @@ def traverse_parents(context):
         if not IPloneSiteRoot.providedBy(obj):
             obj_is_folderish = IFolderish.providedBy(obj)
             obj_is_stuctural = not INonStructuralFolder.providedBy(obj)
-            if (obj_is_folderish and obj_is_stuctural):
-                flag = getattr(obj, 'allow_discussion', None)
+            if obj_is_folderish and obj_is_stuctural:
+                flag = getattr(obj, "allow_discussion", None)
                 if flag is not None:
                     return flag
     return None
 
 
-class ConversationView(object):
-
+class ConversationView:
     def enabled(self):
         if DEXTERITY_INSTALLED and IDexterityContent.providedBy(self.context):
             return self._enabled_for_dexterity_types()
@@ -42,7 +41,7 @@ class ConversationView(object):
             return self._enabled_for_archetypes()
 
     def _enabled_for_archetypes(self):
-        """ Returns True if discussion is enabled for this conversation.
+        """Returns True if discussion is enabled for this conversation.
 
         This method checks five different settings in order to figure out if
         discussion is enabled on a specific content object:
@@ -82,7 +81,7 @@ class ConversationView(object):
                 return False
 
         # If discussion is disabled for the object, bail out
-        obj_flag = getattr(aq_base(context), 'allow_discussion', None)
+        obj_flag = getattr(aq_base(context), "allow_discussion", None)
         if obj_flag is False:
             return False
 
@@ -91,16 +90,16 @@ class ConversationView(object):
         folder_allow_discussion = traverse_parents(context)
 
         if folder_allow_discussion:
-            if not getattr(self, 'allow_discussion', None):
+            if not getattr(self, "allow_discussion", None):
                 return True
         else:
             if obj_flag:
                 return True
 
         # Check if discussion is allowed on the content type
-        portal_types = getToolByName(self, 'portal_types')
+        portal_types = getToolByName(self, "portal_types")
         document_fti = getattr(portal_types, context.portal_type)
-        if not document_fti.getProperty('allow_discussion'):
+        if not document_fti.getProperty("allow_discussion"):
             # If discussion is not allowed on the content type,
             # check if 'allow discussion' is overridden on the content object.
             if not obj_flag:
@@ -109,7 +108,7 @@ class ConversationView(object):
         return True
 
     def _enabled_for_dexterity_types(self):
-        """ Returns True if discussion is enabled for this conversation.
+        """Returns True if discussion is enabled for this conversation.
 
         This method checks five different settings in order to figure out if
         discussion is enable on a specific content object:
@@ -134,11 +133,11 @@ class ConversationView(object):
             return False
 
         # Check if discussion is allowed on the content object
-        if safe_hasattr(context, 'allow_discussion'):
+        if safe_hasattr(context, "allow_discussion"):
             if context.allow_discussion is not None:
                 return context.allow_discussion
 
         # Check if discussion is allowed on the content type
-        portal_types = getToolByName(self, 'portal_types')
+        portal_types = getToolByName(self, "portal_types")
         document_fti = getattr(portal_types, context.portal_type)
-        return document_fti.getProperty('allow_discussion')
+        return document_fti.getProperty("allow_discussion")
diff --git a/plone/app/discussion/browser/moderation.py b/plone/app/discussion/browser/moderation.py
index 99d6216..1d0ee8f 100644
--- a/plone/app/discussion/browser/moderation.py
+++ b/plone/app/discussion/browser/moderation.py
@@ -1,11 +1,10 @@
-# coding: utf-8
 from AccessControl import getSecurityManager
 from AccessControl import Unauthorized
 from Acquisition import aq_inner
 from Acquisition import aq_parent
+from plone.app.discussion.events import CommentDeletedEvent
 from plone.app.discussion.events import CommentPublishedEvent
 from plone.app.discussion.events import CommentTransitionEvent
-from plone.app.discussion.events import CommentDeletedEvent
 from plone.app.discussion.interfaces import _
 from plone.app.discussion.interfaces import IComment
 from plone.app.discussion.interfaces import IReplies
@@ -18,21 +17,20 @@ from zope.event import notify
 
 # Translations for generated values in buttons
 # States
-_('comment_pending', default='pending')
+_("comment_pending", default="pending")
 # _('comment_approved', default='published')
-_('comment_published', default='published')
-_('comment_rejected', default='rejected')
-_('comment_spam', default='marked as spam')
+_("comment_published", default="published")
+_("comment_rejected", default="rejected")
+_("comment_spam", default="marked as spam")
 # Transitions
-_('Recall')
-_('Approve')
-_('Reject')
-_('Spam')
+_("Recall")
+_("Approve")
+_("Reject")
+_("Spam")
 PMF = _
 
 
 class TranslationHelper(BrowserView):
-
     def translate(self, text=""):
         return _(text)
 
@@ -44,22 +42,21 @@ class TranslationHelper(BrowserView):
 class View(BrowserView):
     """Show comment moderation view."""
 
-    template = ViewPageTemplateFile('moderation.pt')
+    template = ViewPageTemplateFile("moderation.pt")
     try:
-        template.id = '@@moderate-comments'
+        template.id = "@@moderate-comments"
     except AttributeError:
         # id is not writeable in Zope 2.12
         pass
 
     def __init__(self, context, request):
-        super(View, self).__init__(context, request)
-        self.workflowTool = getToolByName(self.context, 'portal_workflow')
+        super().__init__(context, request)
+        self.workflowTool = getToolByName(self.context, "portal_workflow")
         self.transitions = []
 
     def __call__(self):
-        self.request.set('disable_border', True)
-        self.request.set('review_state',
-                         self.request.get('review_state', 'pending'))
+        self.request.set("disable_border", True)
+        self.request.set("review_state", self.request.get("review_state", "pending"))
         return self.template()
 
     def comments(self):
@@ -67,15 +64,19 @@ class View(BrowserView):
 
         review_state is string or list of strings.
         """
-        catalog = getToolByName(self.context, 'portal_catalog')
-        if self.request.review_state == 'all':
-            return catalog(object_provides=IComment.__identifier__,
-                           sort_on='created',
-                           sort_order='reverse')
-        return catalog(object_provides=IComment.__identifier__,
-                       review_state=self.request.review_state,
-                       sort_on='created',
-                       sort_order='reverse')
+        catalog = getToolByName(self.context, "portal_catalog")
+        if self.request.review_state == "all":
+            return catalog(
+                object_provides=IComment.__identifier__,
+                sort_on="created",
+                sort_order="reverse",
+            )
+        return catalog(
+            object_provides=IComment.__identifier__,
+            review_state=self.request.review_state,
+            sort_on="created",
+            sort_order="reverse",
+        )
 
     def moderation_enabled(self):
         """Return true if a review workflow is enabled on 'Discussion Item'
@@ -84,11 +85,10 @@ class View(BrowserView):
         A 'review workflow' is characterized by implementing a 'pending'
         workflow state.
         """
-        workflows = self.workflowTool.getChainForPortalType(
-            'Discussion Item')
+        workflows = self.workflowTool.getChainForPortalType("Discussion Item")
         if workflows:
             comment_workflow = self.workflowTool[workflows[0]]
-            if 'pending' in comment_workflow.states:
+            if "pending" in comment_workflow.states:
                 return True
         return False
 
@@ -100,11 +100,10 @@ class View(BrowserView):
         A 'review multipe state workflow' is characterized by implementing
         a 'rejected' workflow state and a 'spam' workflow state.
         """
-        workflows = self.workflowTool.getChainForPortalType(
-            'Discussion Item')
+        workflows = self.workflowTool.getChainForPortalType("Discussion Item")
         if workflows:
             comment_workflow = self.workflowTool[workflows[0]]
-            if 'spam' in comment_workflow.states:
+            if "spam" in comment_workflow.states:
                 return True
         return False
 
@@ -125,27 +124,26 @@ class View(BrowserView):
         """
         if obj:
             transitions = [
-                a for a in self.workflowTool.listActionInfos(object=obj)
-                if a['category'] == 'workflow' and a['allowed']
-                ]
+                a
+                for a in self.workflowTool.listActionInfos(object=obj)
+                if a["category"] == "workflow" and a["allowed"]
+            ]
             return transitions
 
 
 class ModerateCommentsEnabled(BrowserView):
-
     def __call__(self):
         """Returns true if a 'review workflow' is enabled on 'Discussion Item'
-           content type. A 'review workflow' is characterized by implementing
-           a 'pending' workflow state.
+        content type. A 'review workflow' is characterized by implementing
+        a 'pending' workflow state.
         """
         context = aq_inner(self.context)
-        workflowTool = getToolByName(context, 'portal_workflow', None)
-        comment_workflow = workflowTool.getChainForPortalType(
-            'Discussion Item')
+        workflowTool = getToolByName(context, "portal_workflow", None)
+        comment_workflow = workflowTool.getChainForPortalType("Discussion Item")
         if comment_workflow:
             comment_workflow = comment_workflow[0]
             comment_workflow = workflowTool[comment_workflow]
-            if 'pending' in comment_workflow.states:
+            if "pending" in comment_workflow.states:
                 return True
 
         return False
@@ -184,13 +182,15 @@ class DeleteComment(BrowserView):
             content_object.reindexObject()
             notify(CommentDeletedEvent(self.context, comment))
             IStatusMessage(self.context.REQUEST).addStatusMessage(
-                _('Comment deleted.'),
-                type='info')
+                _("Comment deleted."), type="info"
+            )
         came_from = self.context.REQUEST.HTTP_REFERER
         # if the referrer already has a came_from in it, don't redirect back
-        if (len(came_from) == 0 or 'came_from=' in came_from or
-                not getToolByName(
-                content_object, 'portal_url').isURLInPortal(came_from)):
+        if (
+            len(came_from) == 0
+            or "came_from=" in came_from
+            or not getToolByName(content_object, "portal_url").isURLInPortal(came_from)
+        ):
             came_from = content_object.absolute_url()
         return self.context.REQUEST.RESPONSE.redirect(came_from)
 
@@ -198,8 +198,7 @@ class DeleteComment(BrowserView):
         """Returns true if current user has the 'Delete comments'
         permission.
         """
-        return getSecurityManager().checkPermission('Delete comments',
-                                                    aq_inner(reply))
+        return getSecurityManager().checkPermission("Delete comments", aq_inner(reply))
 
 
 class DeleteOwnComment(DeleteComment):
@@ -213,26 +212,23 @@ class DeleteOwnComment(DeleteComment):
     """
 
     def could_delete(self, comment=None):
-        """Returns true if the comment could be deleted if it had no replies.
-        """
+        """Returns true if the comment could be deleted if it had no replies."""
         sm = getSecurityManager()
         comment = comment or aq_inner(self.context)
         userid = sm.getUser().getId()
-        return (
-            sm.checkPermission('Delete own comments', comment) and
-            'Owner' in comment.get_local_roles_for_userid(userid)
-        )
+        return sm.checkPermission(
+            "Delete own comments", comment
+        ) and "Owner" in comment.get_local_roles_for_userid(userid)
 
     def can_delete(self, comment=None):
         comment = comment or self.context
-        return (
-            len(IReplies(aq_inner(comment))) == 0 and
-            self.could_delete(comment=comment)
+        return len(IReplies(aq_inner(comment))) == 0 and self.could_delete(
+            comment=comment
         )
 
     def __call__(self):
         if self.can_delete():
-            super(DeleteOwnComment, self).__call__()
+            super().__call__()
         else:
             raise Unauthorized("You're not allowed to delete this comment.")
 
@@ -262,33 +258,37 @@ class CommentTransition(BrowserView):
         """Call CommentTransition."""
         comment = aq_inner(self.context)
         content_object = aq_parent(aq_parent(comment))
-        workflow_action = self.request.form.get('workflow_action', 'publish')
-        workflowTool = getToolByName(self.context, 'portal_workflow')
+        workflow_action = self.request.form.get("workflow_action", "publish")
+        workflowTool = getToolByName(self.context, "portal_workflow")
         workflowTool.doActionFor(comment, workflow_action)
         comment.reindexObject()
-        content_object.reindexObject(idxs=['total_comments'])
+        content_object.reindexObject(idxs=["total_comments"])
         notify(CommentPublishedEvent(self.context, comment))
         # for complexer workflows:
         notify(CommentTransitionEvent(self.context, comment))
-        comment_state_translated = ''
+        comment_state_translated = ""
         if workflowTool.getWorkflowsFor(comment):
-            review_state_new = workflowTool.getInfoFor(ob=comment, name='review_state')
+            review_state_new = workflowTool.getInfoFor(ob=comment, name="review_state")
             helper = self.context.restrictedTraverse("translationhelper")
-            comment_state_translated = helper.translate_comment_review_state(review_state_new)
+            comment_state_translated = helper.translate_comment_review_state(
+                review_state_new
+            )
 
         msgid = _(
             "comment_transmitted",
-            default='Comment ${comment_state_translated}.',
-            mapping={"comment_state_translated": comment_state_translated})
+            default="Comment ${comment_state_translated}.",
+            mapping={"comment_state_translated": comment_state_translated},
+        )
         translated = self.context.translate(msgid)
-        IStatusMessage(self.request).add(translated, type='info')
+        IStatusMessage(self.request).add(translated, type="info")
 
         came_from = self.context.REQUEST.HTTP_REFERER
         # if the referrer already has a came_from in it, don't redirect back
-        if (len(came_from) == 0
-            or 'came_from=' in came_from
-            or not getToolByName(
-                content_object, 'portal_url').isURLInPortal(came_from)):
+        if (
+            len(came_from) == 0
+            or "came_from=" in came_from
+            or not getToolByName(content_object, "portal_url").isURLInPortal(came_from)
+        ):
             came_from = content_object.absolute_url()
         return self.context.REQUEST.RESPONSE.redirect(came_from)
 
@@ -317,19 +317,19 @@ class BulkActionsView(BrowserView):
     """
 
     def __init__(self, context, request):
-        super(BulkActionsView, self).__init__(context, request)
-        self.workflowTool = getToolByName(context, 'portal_workflow')
+        super().__init__(context, request)
+        self.workflowTool = getToolByName(context, "portal_workflow")
 
     def __call__(self):
         """Call BulkActionsView."""
-        if 'form.select.BulkAction' in self.request:
-            bulkaction = self.request.get('form.select.BulkAction')
-            self.paths = self.request.get('paths')
+        if "form.select.BulkAction" in self.request:
+            bulkaction = self.request.get("form.select.BulkAction")
+            self.paths = self.request.get("paths")
             if self.paths:
-                if bulkaction == '-1':
+                if bulkaction == "-1":
                     # no bulk action was selected
                     pass
-                elif bulkaction == 'delete':
+                elif bulkaction == "delete":
                     self.delete()
                 else:
                     self.transmit(bulkaction)
@@ -346,13 +346,14 @@ class BulkActionsView(BrowserView):
             comment = context.restrictedTraverse(path)
             content_object = aq_parent(aq_parent(comment))
             allowed_transitions = [
-                transition['id'] for transition in self.workflowTool.listActionInfos(object=comment)
-                if transition['category'] == 'workflow' and transition['allowed']
-                ]
+                transition["id"]
+                for transition in self.workflowTool.listActionInfos(object=comment)
+                if transition["category"] == "workflow" and transition["allowed"]
+            ]
             if action in allowed_transitions:
                 self.workflowTool.doActionFor(comment, action)
                 comment.reindexObject()
-                content_object.reindexObject(idxs=['total_comments'])
+                content_object.reindexObject(idxs=["total_comments"])
                 notify(CommentPublishedEvent(content_object, comment))
                 # for complexer workflows:
                 notify(CommentTransitionEvent(self.context, comment))
@@ -370,5 +371,5 @@ class BulkActionsView(BrowserView):
             conversation = aq_parent(comment)
             content_object = aq_parent(conversation)
             del conversation[comment.id]
-            content_object.reindexObject(idxs=['total_comments'])
+            content_object.reindexObject(idxs=["total_comments"])
             notify(CommentDeletedEvent(content_object, comment))
diff --git a/plone/app/discussion/browser/traversal.py b/plone/app/discussion/browser/traversal.py
index 1e2251c..f626621 100644
--- a/plone/app/discussion/browser/traversal.py
+++ b/plone/app/discussion/browser/traversal.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 """Implement the ++comments++ traversal namespace. This should return the
 IDiscussion container for the context, from which traversal will continue
 into an actual comment object.
@@ -15,7 +14,7 @@ from zope.traversing.interfaces import TraversalError
 
 @implementer(ITraversable)
 @adapter(Interface, IBrowserRequest)
-class ConversationNamespace(object):
+class ConversationNamespace:
     """Allow traversal into a conversation via a ++conversation++name
     namespace. The name is the name of an adapter from context to
     IConversation. The special name 'default' will be taken as the default
@@ -29,8 +28,8 @@ class ConversationNamespace(object):
 
     def traverse(self, name, ignore):
 
-        if name == 'default':
-            name = u''
+        if name == "default":
+            name = ""
 
         conversation = queryAdapter(self.context, IConversation, name=name)
         if conversation is None:
diff --git a/plone/app/discussion/browser/validator.py b/plone/app/discussion/browser/validator.py
index d1582e9..9d28bd9 100644
--- a/plone/app/discussion/browser/validator.py
+++ b/plone/app/discussion/browser/validator.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 """Captcha validator, see captcha.txt for design notes.
 """
 from Acquisition import aq_inner
@@ -39,16 +38,17 @@ class CaptchaValidator(validator.SimpleFieldValidator):
     # We adapt the CaptchaValidator class to all form fields (IField)
 
     def validate(self, value):
-        super(CaptchaValidator, self).validate(value)
+        super().validate(value)
 
         registry = queryUtility(IRegistry)
         settings = registry.forInterface(IDiscussionSettings, check=False)
 
-        if settings.captcha in ('captcha', 'recaptcha', 'norobots'):
-            captcha = getMultiAdapter((aq_inner(self.context), self.request),
-                                      name=settings.captcha)
+        if settings.captcha in ("captcha", "recaptcha", "norobots"):
+            captcha = getMultiAdapter(
+                (aq_inner(self.context), self.request), name=settings.captcha
+            )
             if not captcha.verify(input=value):
-                if settings.captcha == 'norobots':
+                if settings.captcha == "norobots":
                     raise WrongNorobotsAnswer
                 else:
                     raise WrongCaptchaCode
@@ -57,5 +57,4 @@ class CaptchaValidator(validator.SimpleFieldValidator):
 
 
 # Register Captcha validator for the Captcha field in the ICaptcha Form
-validator.WidgetValidatorDiscriminators(CaptchaValidator,
-                                        field=ICaptcha['captcha'])
+validator.WidgetValidatorDiscriminators(CaptchaValidator, field=ICaptcha["captcha"])
diff --git a/plone/app/discussion/catalog.py b/plone/app/discussion/catalog.py
index 73c5ab2..6413d11 100644
--- a/plone/app/discussion/catalog.py
+++ b/plone/app/discussion/catalog.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 """Catalog indexers, using plone.indexer. These will populate standard catalog
 indexes with values based on the IComment interface.
 
@@ -7,13 +6,12 @@ Also provide event handlers to actually catalog the comments.
 from DateTime import DateTime
 from plone.app.discussion.interfaces import IComment
 from plone.app.discussion.interfaces import IConversation
+from plone.base.utils import safe_text
 from plone.indexer import indexer
 from plone.uuid.interfaces import IUUID
 from Products.CMFCore.interfaces import IContentish
-from Products.CMFPlone.utils import safe_unicode
 from Products.ZCatalog.interfaces import IZCatalog
 
-import six
 
 MAX_DESCRIPTION = 25
 
@@ -24,7 +22,7 @@ MAX_DESCRIPTION = 25
 def total_comments(object):
     # Total number of comments on a conversation
     # Indexers won't work on old discussion items
-    if object.meta_type != 'Discussion Item':
+    if object.meta_type != "Discussion Item":
         try:
             conversation = IConversation(object)
             return conversation.total_comments()
@@ -38,7 +36,7 @@ def total_comments(object):
 def last_comment_date(object):
     # Date of the latest comment on a conversation
     # Indexers won't work on old discussion items
-    if object.meta_type != 'Discussion Item':
+    if object.meta_type != "Discussion Item":
         try:
             conversation = IConversation(object)
             return conversation.last_comment_date
@@ -52,7 +50,7 @@ def last_comment_date(object):
 def commentators(object):
     # List of commentators on a conversation
     # Indexers won't work on old discussion items
-    if object.meta_type != 'Discussion Item':
+    if object.meta_type != "Discussion Item":
         try:
             conversation = IConversation(object)
             return conversation.public_commentators
@@ -61,6 +59,7 @@ def commentators(object):
             # implemented an adapter for it
             pass
 
+
 # Comment Indexers
 
 
@@ -73,26 +72,24 @@ def title(object):
 def creator(object):
     if not object.creator:
         return
-    value = safe_unicode(object.creator)
-    if six.PY2:
-        return value.encode('utf8')
+    value = safe_text(object.creator)
     return value
 
 
 @indexer(IComment)
 def description(object):
     # Return the first 25 words of the comment text and append ' [...]'
-    text = ' '.join(
-        object.getText(targetMimetype='text/plain').split()[:MAX_DESCRIPTION],
+    text = " ".join(
+        object.getText(targetMimetype="text/plain").split()[:MAX_DESCRIPTION],
     )
     if len(object.getText().split()) > 25:
-        text += ' [...]'
+        text += " [...]"
     return text
 
 
 @indexer(IComment)
 def searchable_text(object):
-    return object.getText(targetMimetype='text/plain')
+    return object.getText(targetMimetype="text/plain")
 
 
 @indexer(IComment)
@@ -106,42 +103,42 @@ def in_response_to(object):
 def effective(object):
     # the catalog index needs Zope DateTime instead of Python datetime
     return DateTime(
-            object.creation_date.year,
-            object.creation_date.month,
-            object.creation_date.day,
-            object.creation_date.hour,
-            object.creation_date.minute,
-            object.creation_date.second,
-            'GMT',
-            )
+        object.creation_date.year,
+        object.creation_date.month,
+        object.creation_date.day,
+        object.creation_date.hour,
+        object.creation_date.minute,
+        object.creation_date.second,
+        "GMT",
+    )
 
 
 @indexer(IComment)
 def created(object):
     # the catalog index needs Zope DateTime instead of Python datetime
     return DateTime(
-            object.creation_date.year,
-            object.creation_date.month,
-            object.creation_date.day,
-            object.creation_date.hour,
-            object.creation_date.minute,
-            object.creation_date.second,
-            'GMT',
-            )
+        object.creation_date.year,
+        object.creation_date.month,
+        object.creation_date.day,
+        object.creation_date.hour,
+        object.creation_date.minute,
+        object.creation_date.second,
+        "GMT",
+    )
 
 
 @indexer(IComment)
 def modified(object):
     # the catalog index needs Zope DateTime instead of Python datetime
     return DateTime(
-            object.modification_date.year,
-            object.modification_date.month,
-            object.modification_date.day,
-            object.modification_date.hour,
-            object.modification_date.minute,
-            object.modification_date.second,
-            'GMT',
-            )
+        object.modification_date.year,
+        object.modification_date.month,
+        object.modification_date.day,
+        object.modification_date.hour,
+        object.modification_date.minute,
+        object.modification_date.second,
+        "GMT",
+    )
 
 
 # Override the conversation indexers for comments
diff --git a/plone/app/discussion/comment.py b/plone/app/discussion/comment.py
index cc1099f..438e726 100644
--- a/plone/app/discussion/comment.py
+++ b/plone/app/discussion/comment.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 """The default comment class and factory.
 """
 from AccessControl import ClassSecurityInfo
@@ -21,14 +20,14 @@ from plone.app.discussion.events import ReplyRemovedEvent
 from plone.app.discussion.interfaces import IComment
 from plone.app.discussion.interfaces import IConversation
 from plone.app.discussion.interfaces import IDiscussionSettings
+from plone.base.interfaces.controlpanel import IMailSchema
+from plone.base.utils import safe_text
 from plone.registry.interfaces import IRegistry
 from Products.CMFCore import permissions
 from Products.CMFCore.CMFCatalogAware import CatalogAware
 from Products.CMFCore.CMFCatalogAware import WorkflowAware
 from Products.CMFCore.DynamicType import DynamicType
 from Products.CMFCore.utils import getToolByName
-from Products.CMFPlone.interfaces.controlpanel import IMailSchema
-from Products.CMFPlone.utils import safe_unicode
 from smtplib import SMTPException
 from zope.annotation.interfaces import IAnnotatable
 from zope.component import getUtility
@@ -40,61 +39,69 @@ from zope.i18nmessageid import Message
 from zope.interface import implementer
 
 import logging
-import six
 
 
 COMMENT_TITLE = _(
-    u'comment_title',
-    default=u'${author_name} on ${content}',
-    )
+    "comment_title",
+    default="${author_name} on ${content}",
+)
 
 MAIL_NOTIFICATION_MESSAGE = _(
-    u'mail_notification_message',
-    default=u'A comment on "${title}" '
-            u'has been posted here: ${link}\n\n'
-            u'---\n'
-            u'${text}\n'
-            u'---\n',
-    )
+    "mail_notification_message",
+    default='A comment on "${title}" '
+    "has been posted here: ${link}\n\n"
+    "---\n"
+    "${text}\n"
+    "---\n",
+)
 
 MAIL_NOTIFICATION_MESSAGE_MODERATOR = _(
-    u'mail_notification_message_moderator2',
-    default=u'A comment on "${title}" '
-            u'has been posted by ${commentator}\n'
-            u'here: ${link}\n\n'
-            u'---\n\n'
-            u'${text}\n\n'
-            u'---\n\n'
-            u'Log in to moderate.\n\n',
-    )
+    "mail_notification_message_moderator2",
+    default='A comment on "${title}" '
+    "has been posted by ${commentator}\n"
+    "here: ${link}\n\n"
+    "---\n\n"
+    "${text}\n\n"
+    "---\n\n"
+    "Log in to moderate.\n\n",
+)
 
-logger = logging.getLogger('plone.app.discussion')
+logger = logging.getLogger("plone.app.discussion")
 
 
 @implementer(IComment)
-class Comment(CatalogAware, WorkflowAware, DynamicType, Traversable,
-              RoleManager, Owned, Implicit, Persistent):
+class Comment(
+    CatalogAware,
+    WorkflowAware,
+    DynamicType,
+    Traversable,
+    RoleManager,
+    Owned,
+    Implicit,
+    Persistent,
+):
     """A comment.
 
     This object attempts to be as lightweight as possible. We implement a
     number of standard methods instead of subclassing, to have total control
     over what goes into the object.
     """
+
     security = ClassSecurityInfo()
 
-    meta_type = portal_type = 'Discussion Item'
+    meta_type = portal_type = "Discussion Item"
     # This needs to be kept in sync with types/Discussion_Item.xml title
-    fti_title = 'Comment'
+    fti_title = "Comment"
 
     __parent__ = None
 
     comment_id = None  # long
     in_reply_to = None  # long
 
-    title = u''
+    title = ""
 
     mime_type = None
-    text = u''
+    text = ""
 
     creator = None
     creation_date = None
@@ -113,19 +120,22 @@ class Comment(CatalogAware, WorkflowAware, DynamicType, Traversable,
 
     def __init__(self):
         self.creation_date = self.modification_date = datetime.utcnow()
-        self.mime_type = 'text/plain'
+        self.mime_type = "text/plain"
 
         user = getSecurityManager().getUser()
         if user and user.getId():
             aclpath = [x for x in user.getPhysicalPath() if x]
-            self._owner = (aclpath, user.getId(),)
+            self._owner = (
+                aclpath,
+                user.getId(),
+            )
             self.__ac_local_roles__ = {
-                user.getId(): ['Owner'],
+                user.getId(): ["Owner"],
             }
 
     @property
     def __name__(self):
-        return self.comment_id and six.text_type(self.comment_id) or None
+        return self.comment_id and str(self.comment_id) or None
 
     @property
     def id(self):
@@ -137,32 +147,30 @@ class Comment(CatalogAware, WorkflowAware, DynamicType, Traversable,
 
     def getText(self, targetMimetype=None):
         """The body text of a comment."""
-        transforms = getToolByName(self, 'portal_transforms')
+        transforms = getToolByName(self, "portal_transforms")
 
         if targetMimetype is None:
-            targetMimetype = 'text/x-html-safe'
+            targetMimetype = "text/x-html-safe"
 
-        sourceMimetype = getattr(self, 'mime_type', None)
+        sourceMimetype = getattr(self, "mime_type", None)
         if sourceMimetype is None:
             registry = queryUtility(IRegistry)
             settings = registry.forInterface(IDiscussionSettings, check=False)
             sourceMimetype = settings.text_transform
         text = self.text
         if text is None:
-            return ''
-        if six.PY2 and isinstance(text, six.text_type):
-            text = text.encode('utf8')
+            return ""
         transform = transforms.convertTo(
-            targetMimetype,
-            text,
-            context=self,
-            mimetype=sourceMimetype)
+            targetMimetype, text, context=self, mimetype=sourceMimetype
+        )
         if transform:
             return transform.getData()
         else:
-            logger = logging.getLogger('plone.app.discussion')
-            msg = u'Transform "{0}" => "{1}" not available. Failed to ' \
-                  u'transform comment "{2}".'
+            logger = logging.getLogger("plone.app.discussion")
+            msg = (
+                'Transform "{0}" => "{1}" not available. Failed to '
+                'transform comment "{2}".'
+            )
             logger.error(
                 msg.format(
                     sourceMimetype,
@@ -182,8 +190,8 @@ class Comment(CatalogAware, WorkflowAware, DynamicType, Traversable,
             author_name = translate(
                 Message(
                     _(
-                        u'label_anonymous',
-                        default=u'Anonymous',
+                        "label_anonymous",
+                        default="Anonymous",
                     ),
                 ),
             )
@@ -194,9 +202,14 @@ class Comment(CatalogAware, WorkflowAware, DynamicType, Traversable,
         # conversation, the parent of the conversation is the content object).
         content = aq_base(self.__parent__.__parent__)
         title = translate(
-            Message(COMMENT_TITLE,
-                    mapping={'author_name': safe_unicode(author_name),
-                             'content': safe_unicode(content.Title())}))
+            Message(
+                COMMENT_TITLE,
+                mapping={
+                    "author_name": safe_text(author_name),
+                    "content": safe_text(content.Title()),
+                },
+            )
+        )
         return title
 
     def Creator(self):
@@ -224,25 +237,23 @@ CommentFactory = Factory(Comment)
 
 
 def notify_workflow(obj, event):
-    """Tell the workflow tool when a comment is added
-    """
-    tool = getToolByName(obj, 'portal_workflow', None)
+    """Tell the workflow tool when a comment is added"""
+    tool = getToolByName(obj, "portal_workflow", None)
     if tool is not None:
         tool.notifyCreated(obj)
 
 
 def notify_content_object(obj, event):
-    """Tell the content object when a comment is added
-    """
+    """Tell the content object when a comment is added"""
     content_obj = aq_parent(aq_parent(obj))
-    content_obj.reindexObject(idxs=('total_comments',
-                                    'last_comment_date',
-                                    'commentators'))
+    content_obj.reindexObject(
+        idxs=("total_comments", "last_comment_date", "commentators")
+    )
 
 
 def notify_content_object_deleted(obj, event):
     """Remove all comments of a content object when the content object has been
-       deleted.
+    deleted.
     """
     if IAnnotatable.providedBy(obj):
         conversation = IConversation(obj)
@@ -251,40 +262,40 @@ def notify_content_object_deleted(obj, event):
 
 
 def notify_comment_added(obj, event):
-    """ Notify custom discussion events when a comment is added or replied
-    """
+    """Notify custom discussion events when a comment is added or replied"""
     conversation = aq_parent(obj)
     context = aq_parent(conversation)
-    if getattr(obj, 'in_reply_to', None):
+    if getattr(obj, "in_reply_to", None):
         return notify(ReplyAddedEvent(context, obj))
     return notify(CommentAddedEvent(context, obj))
 
 
 def notify_comment_modified(obj, event):
-    """ Notify custom discussion events when a comment, or a reply, is modified
-    """
+    """Notify custom discussion events when a comment, or a reply, is modified"""
     conversation = aq_parent(obj)
     context = aq_parent(conversation)
-    if getattr(obj, 'in_reply_to', None):
+    if getattr(obj, "in_reply_to", None):
         return notify(ReplyModifiedEvent(context, obj))
     return notify(CommentModifiedEvent(context, obj))
 
 
 def notify_comment_removed(obj, event):
-    """ Notify custom discussion events when a comment or reply is removed
-    """
+    """Notify custom discussion events when a comment or reply is removed"""
     conversation = aq_parent(obj)
     context = aq_parent(conversation)
-    if getattr(obj, 'in_reply_to', None):
+    if getattr(obj, "in_reply_to", None):
         return notify(ReplyRemovedEvent(context, obj))
     return notify(CommentRemovedEvent(context, obj))
 
 
 def notify_content_object_moved(obj, event):
-    """Update all comments of a content object that has been moved.
-    """
-    if event.oldParent is None or event.newParent is None \
-            or event.oldName is None or event.newName is None:
+    """Update all comments of a content object that has been moved."""
+    if (
+        event.oldParent is None
+        or event.newParent is None
+        or event.oldName is None
+        or event.newName is None
+    ):
         return
 
     # This method is also called for sublocations of moved objects. We
@@ -293,21 +304,19 @@ def notify_content_object_moved(obj, event):
     # in the object hierarchy. The object is already moved at this point. so
     # obj.getPhysicalPath retruns the new path get the part of the path that
     # was moved.
-    moved_path = obj.getPhysicalPath()[
-        len(event.newParent.getPhysicalPath()) + 1:
-    ]
+    moved_path = obj.getPhysicalPath()[len(event.newParent.getPhysicalPath()) + 1 :]
 
     # Remove comments at the old location from catalog
-    catalog = getToolByName(obj, 'portal_catalog')
-    old_path = '/'.join(
-        event.oldParent.getPhysicalPath() +
-        (event.oldName,) +
-        moved_path,
+    catalog = getToolByName(obj, "portal_catalog")
+    old_path = "/".join(
+        event.oldParent.getPhysicalPath() + (event.oldName,) + moved_path,
+    )
+    brains = catalog.searchResults(
+        dict(
+            path={"query": old_path},
+            portal_type="Discussion Item",
+        )
     )
-    brains = catalog.searchResults(dict(
-        path={'query': old_path},
-        portal_type='Discussion Item',
-    ))
     for brain in brains:
         catalog.uncatalog_object(brain.getPath())
     # Reindex comment at the new location
@@ -320,11 +329,11 @@ def notify_content_object_moved(obj, event):
 def notify_user(obj, event):
     """Tell users when a comment has been added.
 
-       This method composes and sends emails to all users that have added a
-       comment to this conversation and enabled user notification.
+    This method composes and sends emails to all users that have added a
+    comment to this conversation and enabled user notification.
 
-       This requires the user_notification setting to be enabled in the
-       discussion control panel.
+    This requires the user_notification setting to be enabled in the
+    discussion control panel.
     """
 
     # Check if user notification is enabled
@@ -334,9 +343,9 @@ def notify_user(obj, event):
         return
 
     # Get informations that are necessary to send an email
-    mail_host = getToolByName(obj, 'MailHost')
+    mail_host = getToolByName(obj, "MailHost")
     registry = getUtility(IRegistry)
-    mail_settings = registry.forInterface(IMailSchema, prefix='plone')
+    mail_settings = registry.forInterface(IMailSchema, prefix="plone")
     sender = mail_settings.email_from_address
 
     # Check if a sender address is available
@@ -360,15 +369,14 @@ def notify_user(obj, event):
     if not emails:
         return
 
-    subject = translate(_(u'A comment has been posted.'),
-                        context=obj.REQUEST)
+    subject = translate(_("A comment has been posted."), context=obj.REQUEST)
     message = translate(
         Message(
             MAIL_NOTIFICATION_MESSAGE,
             mapping={
-                'title': safe_unicode(content_object.title),
-                'link': content_object.absolute_url() + '/view#' + obj.id,
-                'text': obj.text,
+                "title": safe_text(content_object.title),
+                "link": content_object.absolute_url() + "/view#" + obj.id,
+                "text": obj.text,
             },
         ),
         context=obj.REQUEST,
@@ -381,12 +389,11 @@ def notify_user(obj, event):
                 email,
                 sender,
                 subject,
-                charset='utf-8',
+                charset="utf-8",
             )
         except SMTPException:
             logger.error(
-                'SMTP exception while trying to send an ' +
-                'email from %s to %s',
+                "SMTP exception while trying to send an " + "email from %s to %s",
                 sender,
                 email,
             )
@@ -395,15 +402,15 @@ def notify_user(obj, event):
 def notify_moderator(obj, event):
     """Tell the moderator when a comment needs attention.
 
-       This method sends an email to the moderator if comment moderation a new
-       comment has been added that needs to be approved.
+    This method sends an email to the moderator if comment moderation a new
+    comment has been added that needs to be approved.
 
-       The moderator_notification setting has to be enabled in the discussion
-       control panel.
+    The moderator_notification setting has to be enabled in the discussion
+    control panel.
 
-       Configure the moderator e-mail address in the discussion control panel.
-       If no moderator is configured but moderator notifications are turned on,
-       the site admin email (from the mail control panel) will be used.
+    Configure the moderator e-mail address in the discussion control panel.
+    If no moderator is configured but moderator notifications are turned on,
+    the site admin email (from the mail control panel) will be used.
     """
     # Check if moderator notification is enabled
     registry = queryUtility(IRegistry)
@@ -412,9 +419,9 @@ def notify_moderator(obj, event):
         return
 
     # Get informations that are necessary to send an email
-    mail_host = getToolByName(obj, 'MailHost')
+    mail_host = getToolByName(obj, "MailHost")
     registry = getUtility(IRegistry)
-    mail_settings = registry.forInterface(IMailSchema, prefix='plone')
+    mail_settings = registry.forInterface(IMailSchema, prefix="plone")
     sender = mail_settings.email_from_address
 
     if settings.moderator_email:
@@ -430,22 +437,23 @@ def notify_moderator(obj, event):
     content_object = aq_parent(conversation)
 
     # Compose email
-    subject = translate(_(u'A comment has been posted.'), context=obj.REQUEST)
+    subject = translate(_("A comment has been posted."), context=obj.REQUEST)
     message = translate(
         Message(
             MAIL_NOTIFICATION_MESSAGE_MODERATOR,
             mapping={
-                'title': safe_unicode(content_object.title),
-                'link': content_object.absolute_url() + '/view#' + obj.id,
-                'text': obj.text,
-                'commentator': obj.author_email or translate(
-                        Message(
-                            _(
-                                u'label_anonymous',
-                                default=u'Anonymous',
-                            ),
+                "title": safe_text(content_object.title),
+                "link": content_object.absolute_url() + "/view#" + obj.id,
+                "text": obj.text,
+                "commentator": obj.author_email
+                or translate(
+                    Message(
+                        _(
+                            "label_anonymous",
+                            default="Anonymous",
                         ),
-                    )
+                    ),
+                ),
             },
         ),
         context=obj.REQUEST,
@@ -453,12 +461,12 @@ def notify_moderator(obj, event):
 
     # Send email
     try:
-        mail_host.send(message, mto, sender, subject, charset='utf-8')
+        mail_host.send(message, mto, sender, subject, charset="utf-8")
     except SMTPException as e:
         logger.error(
-            'SMTP exception (%s) while trying to send an ' +
-            'email notification to the comment moderator ' +
-            '(from %s to %s, message: %s)',
+            "SMTP exception (%s) while trying to send an "
+            + "email notification to the comment moderator "
+            + "(from %s to %s, message: %s)",
             e,
             sender,
             mto,
diff --git a/plone/app/discussion/configure.zcml b/plone/app/discussion/configure.zcml
index aabd851..fb72cee 100644
--- a/plone/app/discussion/configure.zcml
+++ b/plone/app/discussion/configure.zcml
@@ -39,7 +39,7 @@
         description="Commenting infrastructure for Plone"
         directory="profiles/default"
         provides="Products.GenericSetup.interfaces.EXTENSION"
-        for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+        for="plone.base.interfaces.IPloneSiteRoot"
         />
     <!-- For upgrade steps see upgrades.zcml. -->
 
diff --git a/plone/app/discussion/contentrules.py b/plone/app/discussion/contentrules.py
index c8f602a..bc752b2 100644
--- a/plone/app/discussion/contentrules.py
+++ b/plone/app/discussion/contentrules.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 """ Content rules handlers
 """
 from plone.app.discussion import _
@@ -7,101 +6,94 @@ from plone.app.discussion import _
 try:
     from plone.stringinterp.adapters import BaseSubstitution
 except ImportError:
-    class BaseSubstitution(object):
-        """ Fallback class if plone.stringinterp is not available
-        """
+
+    class BaseSubstitution:
+        """Fallback class if plone.stringinterp is not available"""
 
         def __init__(self, context, **kwargs):
             self.context = context
 
+
 try:
     from plone.app.contentrules.handlers import execute
 except ImportError:
+
     def execute(context, event):
         return False
 
 
 def execute_comment(event):
-    """ Execute comment content rules
-    """
+    """Execute comment content rules"""
     execute(event.object, event)
 
 
 class CommentSubstitution(BaseSubstitution):
-    """ Comment string substitution
-    """
+    """Comment string substitution"""
 
     def __init__(self, context, **kwargs):
-        super(CommentSubstitution, self).__init__(context, **kwargs)
+        super().__init__(context, **kwargs)
 
     @property
     def event(self):
-        """ event that triggered the content rule
-        """
-        return self.context.REQUEST.get('event')
+        """event that triggered the content rule"""
+        return self.context.REQUEST.get("event")
 
     @property
     def comment(self):
-        """ Get changed inline comment
-        """
+        """Get changed inline comment"""
         return self.event.comment
 
 
 class Id(CommentSubstitution):
-    """ Comment id string substitution
-    """
-    category = _(u'Comments')
-    description = _(u'Comment id')
+    """Comment id string substitution"""
+
+    category = _("Comments")
+    description = _("Comment id")
 
     def safe_call(self):
-        """ Safe call
-        """
-        return getattr(self.comment, 'comment_id', u'')
+        """Safe call"""
+        return getattr(self.comment, "comment_id", "")
 
 
 class Text(CommentSubstitution):
-    """ Comment text
-    """
-    category = _(u'Comments')
-    description = _(u'Comment text')
+    """Comment text"""
+
+    category = _("Comments")
+    description = _("Comment text")
 
     def safe_call(self):
-        """ Safe call
-        """
-        return getattr(self.comment, 'text', u'')
+        """Safe call"""
+        return getattr(self.comment, "text", "")
 
 
 class AuthorUserName(CommentSubstitution):
-    """ Comment author user name string substitution
-    """
-    category = _(u'Comments')
-    description = _(u'Comment author user name')
+    """Comment author user name string substitution"""
+
+    category = _("Comments")
+    description = _("Comment author user name")
 
     def safe_call(self):
-        """ Safe call
-        """
-        return getattr(self.comment, 'author_username', u'')
+        """Safe call"""
+        return getattr(self.comment, "author_username", "")
 
 
 class AuthorFullName(CommentSubstitution):
-    """ Comment author full name string substitution
-    """
-    category = _(u'Comments')
-    description = _(u'Comment author full name')
+    """Comment author full name string substitution"""
+
+    category = _("Comments")
+    description = _("Comment author full name")
 
     def safe_call(self):
-        """ Safe call
-        """
-        return getattr(self.comment, 'author_name', u'')
+        """Safe call"""
+        return getattr(self.comment, "author_name", "")
 
 
 class AuthorEmail(CommentSubstitution):
-    """ Comment author email string substitution
-    """
-    category = _(u'Comments')
-    description = _(u'Comment author email')
+    """Comment author email string substitution"""
+
+    category = _("Comments")
+    description = _("Comment author email")
 
     def safe_call(self):
-        """ Safe call
-        """
-        return getattr(self.comment, 'author_email', u'')
+        """Safe call"""
+        return getattr(self.comment, "author_email", "")
diff --git a/plone/app/discussion/conversation.py b/plone/app/discussion/conversation.py
index ae13301..1cdb266 100644
--- a/plone/app/discussion/conversation.py
+++ b/plone/app/discussion/conversation.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 """The conversation and replies adapters
 
 The conversation is responsible for storing all comments. It provides a
@@ -10,6 +9,10 @@ manipulate the same data structures, but provide an API for finding and
 manipulating the comments directly in reply to a particular comment or at the
 top level of the conversation.
 """
+from .comment import Comment
+from .interfaces import DISCUSSION_ANNOTATION_KEY as ANNOTATION_KEY
+from .interfaces import IConversation
+from .interfaces import IReplies
 from AccessControl.SpecialUsers import nobody as user_nobody
 from Acquisition import aq_base
 from Acquisition import aq_inner
@@ -22,11 +25,7 @@ from OFS.event import ObjectWillBeAddedEvent
 from OFS.event import ObjectWillBeRemovedEvent
 from OFS.Traversable import Traversable
 from persistent import Persistent
-from plone.app.discussion.comment import Comment
-from plone.app.discussion.interfaces import IConversation
-from plone.app.discussion.interfaces import IReplies
-from Products.CMFPlone import DISCUSSION_ANNOTATION_KEY as ANNOTATION_KEY
-from Products.CMFPlone.interfaces import IHideFromBreadcrumbs
+from plone.base.interfaces import IHideFromBreadcrumbs
 from zope.annotation.interfaces import IAnnotatable
 from zope.annotation.interfaces import IAnnotations
 from zope.component import adapter
@@ -37,7 +36,6 @@ from zope.lifecycleevent import ObjectAddedEvent
 from zope.lifecycleevent import ObjectCreatedEvent
 from zope.lifecycleevent import ObjectRemovedEvent
 
-import six
 import time
 
 
@@ -51,7 +49,7 @@ class Conversation(Traversable, Persistent, Explicit):
 
     __allow_access_to_unprotected_subobjects__ = True
 
-    def __init__(self, id='++conversation++default'):
+    def __init__(self, id="++conversation++default"):
         self.id = id
 
         # username -> count of comments; key is removed when count reaches 0
@@ -72,12 +70,11 @@ class Conversation(Traversable, Persistent, Explicit):
 
     def enabled(self):
         parent = aq_inner(self.__parent__)
-        return parent.restrictedTraverse('@@conversation_view').enabled()
+        return parent.restrictedTraverse("@@conversation_view").enabled()
 
     def total_comments(self):
         public_comments = [
-            x for x in self.values()
-            if user_nobody.has_permission('View', x)
+            x for x in self.values() if user_nobody.has_permission("View", x)
         ]
         return len(public_comments)
 
@@ -88,7 +85,7 @@ class Conversation(Traversable, Persistent, Explicit):
         comment_keys = self._comments.keys()
         for comment_key in reversed(comment_keys):
             comment = self._comments[comment_key]
-            if user_nobody.has_permission('View', comment):
+            if user_nobody.has_permission("View", comment):
                 return comment.creation_date
         return None
 
@@ -100,7 +97,7 @@ class Conversation(Traversable, Persistent, Explicit):
     def public_commentators(self):
         retval = set()
         for comment in self._comments.values():
-            if not user_nobody.has_permission('View', comment):
+            if not user_nobody.has_permission("View", comment):
                 continue
             retval.add(comment.author_username)
         return tuple(retval)
@@ -109,8 +106,7 @@ class Conversation(Traversable, Persistent, Explicit):
         return self._comments.keys()
 
     def getComments(self, start=0, size=None):
-        """Get unthreaded comments
-        """
+        """Get unthreaded comments"""
         count = 0
         for comment in self._comments.values(min=start):
             # Yield the acquisition wrapped comment
@@ -121,20 +117,18 @@ class Conversation(Traversable, Persistent, Explicit):
                 return
 
     def getThreads(self, start=0, size=None, root=0, depth=None):
-        """Get threaded comments
-        """
+        """Get threaded comments"""
 
         def recurse(comment_id, d=0):
             # Yield the current comment before we look for its children
-            yield {'id': comment_id, 'comment': self[comment_id], 'depth': d}
+            yield {"id": comment_id, "comment": self[comment_id], "depth": d}
 
             # Recurse if there are children and we are not out of our depth
             if depth is None or d + 1 < depth:
                 children = self._children.get(comment_id, None)
                 if children is not None:
                     for child_id in children:
-                        for value in recurse(child_id, d + 1):
-                            yield value
+                        yield from recurse(child_id, d + 1)
 
         # Find top level threads
         comments = self._children.get(root, None)
@@ -148,8 +142,7 @@ class Conversation(Traversable, Persistent, Explicit):
                     return
 
                 # Let the closure recurse
-                for value in recurse(comment_id):
-                    yield value
+                yield from recurse(comment_id)
 
     def addComment(self, comment):
         """Add a new comment. The parent id should have been set already. The
@@ -209,8 +202,7 @@ class Conversation(Traversable, Persistent, Explicit):
         return int(key) in self._comments
 
     def __getitem__(self, key):
-        """Get an item by its int key
-        """
+        """Get an item by its int key"""
         try:
             comment_id = int(key)
         except ValueError:
@@ -218,8 +210,7 @@ class Conversation(Traversable, Persistent, Explicit):
         return self._comments[comment_id].__of__(self)
 
     def __delitem__(self, key, suppress_container_modified=False):
-        """Delete an item by its int key
-        """
+        """Delete an item by its int key"""
 
         key = int(key)
 
@@ -269,21 +260,30 @@ class Conversation(Traversable, Persistent, Explicit):
         return self._comments.keys()
 
     def items(self):
-        return [(i[0], i[1].__of__(self),) for i in self._comments.items()]
+        return [
+            (
+                i[0],
+                i[1].__of__(self),
+            )
+            for i in self._comments.items()
+        ]
 
     def values(self):
         return [v.__of__(self) for v in self._comments.values()]
 
     def iterkeys(self):
-        return six.iterkeys(self._comments)
+        return self._comments.keys()
 
     def itervalues(self):
-        for v in six.itervalues(self._comments):
+        for v in self._comments.values():
             yield v.__of__(self)
 
     def iteritems(self):
-        for k, v in six.iteritems(self._comments):
-            yield (k, v.__of__(self),)
+        for k, v in self._comments.items():
+            yield (
+                k,
+                v.__of__(self),
+            )
 
     def allowedContentTypes(self):
         return []
@@ -309,6 +309,7 @@ try:
 except ImportError:
     pass
 else:
+
     @implementer(IConversation)  # pragma: no cover
     @adapter(IAnnotatable)  # pragma: no cover
     def conversationCanonicalAdapterFactory(content):  # pragma: no cover
@@ -327,7 +328,7 @@ else:
 
 @implementer(IReplies)
 @adapter(Conversation)  # relies on implementation details
-class ConversationReplies(object):
+class ConversationReplies:
     """An IReplies adapter for conversations.
 
     This makes it easy to work with top-level comments.
@@ -350,16 +351,14 @@ class ConversationReplies(object):
         return int(key) in self.children
 
     def __getitem__(self, key):
-        """Get an item by its int key
-        """
+        """Get an item by its int key"""
         key = int(key)
         if key not in self.children:
             raise KeyError(key)
         return self.conversation[key]
 
     def __delitem__(self, key):
-        """Delete an item by its int key
-        """
+        """Delete an item by its int key"""
         key = int(key)
         if key not in self.children:
             raise KeyError(key)
@@ -392,7 +391,10 @@ class ConversationReplies(object):
 
     def iteritems(self):
         for key in self.children:
-            yield (key, self.conversation[key],)
+            yield (
+                key,
+                self.conversation[key],
+            )
 
     @property
     def children(self):
@@ -418,11 +420,12 @@ class CommentReplies(ConversationReplies):
         self.conversation = aq_parent(self.comment)
         conversation_has_no_children = not hasattr(
             self.conversation,
-            '_children',
+            "_children",
         )
         if self.conversation is None or conversation_has_no_children:
-            raise TypeError("This adapter doesn't know what to do with the "
-                            'parent conversation')
+            raise TypeError(
+                "This adapter doesn't know what to do with the " "parent conversation"
+            )
 
         self.comment_id = self.comment.comment_id
 
diff --git a/plone/app/discussion/events.py b/plone/app/discussion/events.py
index e2ecc02..3444bbc 100644
--- a/plone/app/discussion/events.py
+++ b/plone/app/discussion/events.py
@@ -1,13 +1,12 @@
-# -*- coding: utf-8 -*-
 """ Custom discussion events
 """
 from plone.app.discussion.interfaces import ICommentAddedEvent
-from plone.app.discussion.interfaces import ICommentModifiedEvent
-from plone.app.discussion.interfaces import ICommentRemovedEvent
-from plone.app.discussion.interfaces import IDiscussionEvent
 from plone.app.discussion.interfaces import ICommentDeletedEvent
+from plone.app.discussion.interfaces import ICommentModifiedEvent
 from plone.app.discussion.interfaces import ICommentPublishedEvent
+from plone.app.discussion.interfaces import ICommentRemovedEvent
 from plone.app.discussion.interfaces import ICommentTransitionEvent
+from plone.app.discussion.interfaces import IDiscussionEvent
 from plone.app.discussion.interfaces import IReplyAddedEvent
 from plone.app.discussion.interfaces import IReplyModifiedEvent
 from plone.app.discussion.interfaces import IReplyRemovedEvent
@@ -15,9 +14,8 @@ from zope.interface import implementer
 
 
 @implementer(IDiscussionEvent)
-class DiscussionEvent(object):
-    """ Custom event
-    """
+class DiscussionEvent:
+    """Custom event"""
 
     def __init__(self, context, comment, **kwargs):
         self.object = context
@@ -28,55 +26,47 @@ class DiscussionEvent(object):
         # Add event to the request to be able to access comment attributes
         # in content-rules dynamic strings
         request = context.REQUEST
-        request.set('event', self)
+        request.set("event", self)
 
 
 @implementer(ICommentAddedEvent)
 class CommentAddedEvent(DiscussionEvent):
-    """ Event to be triggered when a Comment is added
-    """
+    """Event to be triggered when a Comment is added"""
 
 
 @implementer(ICommentModifiedEvent)
 class CommentModifiedEvent(DiscussionEvent):
-    """ Event to be triggered when a Comment is modified
-    """
+    """Event to be triggered when a Comment is modified"""
 
 
 @implementer(ICommentRemovedEvent)
 class CommentRemovedEvent(DiscussionEvent):
-    """ Event to be triggered when a Comment is removed
-    """
+    """Event to be triggered when a Comment is removed"""
 
 
 @implementer(IReplyAddedEvent)
 class ReplyAddedEvent(DiscussionEvent):
-    """ Event to be triggered when a Comment reply is added
-    """
+    """Event to be triggered when a Comment reply is added"""
 
 
 @implementer(IReplyModifiedEvent)
 class ReplyModifiedEvent(DiscussionEvent):
-    """ Event to be triggered when a Comment reply is modified
-    """
+    """Event to be triggered when a Comment reply is modified"""
 
 
 @implementer(IReplyRemovedEvent)
 class ReplyRemovedEvent(DiscussionEvent):
-    """ Event to be triggered when a Comment reply is removed
-    """
+    """Event to be triggered when a Comment reply is removed"""
 
 
 @implementer(ICommentDeletedEvent)
 class CommentDeletedEvent(DiscussionEvent):
-    """ Event to be triggered when a Comment is deleted
-    """
+    """Event to be triggered when a Comment is deleted"""
 
 
 @implementer(ICommentPublishedEvent)
 class CommentPublishedEvent(DiscussionEvent):
-    """ Event to be triggered when a Comment is publicated
-    """
+    """Event to be triggered when a Comment is publicated"""
 
 
 @implementer(ICommentTransitionEvent)
diff --git a/plone/app/discussion/interfaces.py b/plone/app/discussion/interfaces.py
index 76a0cee..e53628d 100644
--- a/plone/app/discussion/interfaces.py
+++ b/plone/app/discussion/interfaces.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 """Interfaces for plone.app.discussion
 """
 from plone.app.discussion import _
@@ -12,11 +11,14 @@ from zope.interface.common.mapping import IIterableMapping
 from zope.interface.interfaces import IObjectEvent
 
 
+DISCUSSION_ANNOTATION_KEY = "plone.app.discussion:conversation"
+
+
 def isEmail(value):
     portal = getUtility(ISiteRoot)
-    reg_tool = getToolByName(portal, 'portal_registration')
+    reg_tool = getToolByName(portal, "portal_registration")
     if not (value and reg_tool.isValidEmail(value)):
-        raise Invalid(_('Invalid email address.'))
+        raise Invalid(_("Invalid email address."))
     return True
 
 
@@ -42,25 +44,24 @@ class IConversation(IIterableMapping):
     """
 
     total_comments = schema.Int(
-        title=_(u'Total number of public comments on this item'),
+        title=_("Total number of public comments on this item"),
         min=0,
         readonly=True,
     )
 
     last_comment_date = schema.Date(
-        title=_(u'Date of the most recent public comment'),
+        title=_("Date of the most recent public comment"),
         readonly=True,
     )
 
     commentators = schema.Set(
-        title=_(u'The set of unique commentators (usernames)'),
+        title=_("The set of unique commentators (usernames)"),
         readonly=True,
     )
 
     public_commentators = schema.Set(
         title=_(
-            u'The set of unique commentators (usernames) '
-            u'of published_comments',
+            "The set of unique commentators (usernames) " "of published_comments",
         ),
         readonly=True,
     )
@@ -72,8 +73,7 @@ class IConversation(IIterableMapping):
         """
 
     def __delitem__(key):
-        """Delete the comment with the given key. The key is a long id.
-        """
+        """Delete the comment with the given key. The key is a long id."""
 
     def getComments(start=0, size=None):
         """Return an iterator of comment objects for rendering.
@@ -130,8 +130,7 @@ class IReplies(IIterableMapping):
         """
 
     def __delitem__(key):
-        """Delete the comment with the given key. The key is a long id.
-        """
+        """Delete the comment with the given key. The key is a long id."""
 
 
 class IComment(Interface):
@@ -141,61 +140,58 @@ class IComment(Interface):
     """
 
     portal_type = schema.ASCIILine(
-        title=_(u'Portal type'),
-        default='Discussion Item',
+        title=_("Portal type"),
+        default="Discussion Item",
     )
 
-    __parent__ = schema.Object(
-        title=_(u'Conversation'), schema=Interface)
+    __parent__ = schema.Object(title=_("Conversation"), schema=Interface)
 
-    __name__ = schema.TextLine(title=_(u'Name'))
+    __name__ = schema.TextLine(title=_("Name"))
 
-    comment_id = schema.Int(
-        title=_(u'A comment id unique to this conversation'))
+    comment_id = schema.Int(title=_("A comment id unique to this conversation"))
 
     in_reply_to = schema.Int(
-        title=_(u'Id of comment this comment is in reply to'),
+        title=_("Id of comment this comment is in reply to"),
         required=False,
     )
 
     # for logged in comments - set to None for anonymous
-    author_username = schema.TextLine(title=_(u'Name'), required=False)
+    author_username = schema.TextLine(title=_("Name"), required=False)
 
     # for anonymous comments only, set to None for logged in comments
-    author_name = schema.TextLine(title=_(u'Name'), required=False)
-    author_email = schema.TextLine(title=_(u'Email'),
-                                   required=False,
-                                   constraint=isEmail,
-                                   )
+    author_name = schema.TextLine(title=_("Name"), required=False)
+    author_email = schema.TextLine(
+        title=_("Email"),
+        required=False,
+        constraint=isEmail,
+    )
 
-    title = schema.TextLine(title=_(u'label_subject',
-                                    default=u'Subject'))
+    title = schema.TextLine(title=_("label_subject", default="Subject"))
 
-    mime_type = schema.ASCIILine(title=_(u'MIME type'), default='text/plain')
+    mime_type = schema.ASCIILine(title=_("MIME type"), default="text/plain")
     text = schema.Text(
         title=_(
-            u'label_comment',
-            default=u'Comment',
+            "label_comment",
+            default="Comment",
         ),
     )
 
     user_notification = schema.Bool(
         title=_(
-            u'Notify me of new comments via email.',
+            "Notify me of new comments via email.",
         ),
         required=False,
     )
 
-    creator = schema.TextLine(title=_(u'Username of the commenter'))
-    creation_date = schema.Date(title=_(u'Creation date'))
-    modification_date = schema.Date(title=_(u'Modification date'))
+    creator = schema.TextLine(title=_("Username of the commenter"))
+    creation_date = schema.Date(title=_("Creation date"))
+    modification_date = schema.Date(title=_("Modification date"))
 
 
 class ICaptcha(Interface):
-    """Captcha/ReCaptcha text field to extend the existing comment form.
-    """
-    captcha = schema.TextLine(title=_(u'Captcha'),
-                              required=False)
+    """Captcha/ReCaptcha text field to extend the existing comment form."""
+
+    captcha = schema.TextLine(title=_("Captcha"), required=False)
 
 
 class IDiscussionSettings(Interface):
@@ -210,40 +206,38 @@ class IDiscussionSettings(Interface):
     # - Search control panel: Show comments in search results
 
     globally_enabled = schema.Bool(
-        title=_(u'label_globally_enabled',
-                default=u'Globally enable comments'),
+        title=_("label_globally_enabled", default="Globally enable comments"),
         description=_(
-            u'help_globally_enabled',
-            default=u'If selected, users are able to post comments on the '
-                    u'site. However, you will still need to enable comments '
-                    u'for specific content types, folders or content '
-                    u'objects before users will be able to post comments.',
+            "help_globally_enabled",
+            default="If selected, users are able to post comments on the "
+            "site. However, you will still need to enable comments "
+            "for specific content types, folders or content "
+            "objects before users will be able to post comments.",
         ),
         required=False,
         default=False,
     )
 
     anonymous_comments = schema.Bool(
-        title=_(u'label_anonymous_comments',
-                default='Enable anonymous comments'),
+        title=_("label_anonymous_comments", default="Enable anonymous comments"),
         description=_(
-            u'help_anonymous_comments',
-            default=u'If selected, anonymous users are able to post '
-                    u'comments without logging in. It is highly '
-                    u'recommended to use a captcha solution to prevent '
-                    u'spam if this setting is enabled.',
+            "help_anonymous_comments",
+            default="If selected, anonymous users are able to post "
+            "comments without logging in. It is highly "
+            "recommended to use a captcha solution to prevent "
+            "spam if this setting is enabled.",
         ),
         required=False,
         default=False,
     )
 
     anonymous_email_enabled = schema.Bool(
-        title=_(u'label_anonymous_email_enabled',
-                default=u'Enable anonymous email field'),
+        title=_(
+            "label_anonymous_email_enabled", default="Enable anonymous email field"
+        ),
         description=_(
-            u'help_anonymous_email_enabled',
-            default=u'If selected, anonymous user will have to '
-                    u'give their email.',
+            "help_anonymous_email_enabled",
+            default="If selected, anonymous user will have to " "give their email.",
         ),
         required=False,
         default=False,
@@ -251,130 +245,137 @@ class IDiscussionSettings(Interface):
 
     moderation_enabled = schema.Bool(
         title=_(
-            u'label_moderation_enabled',
-            default='Enable comment moderation',
+            "label_moderation_enabled",
+            default="Enable comment moderation",
         ),
         description=_(
-            u'help_moderation_enabled',
-            default=u'If selected, comments will enter a "Pending" state '
-                    u'in which they are invisible to the public. A user '
-                    u'with the "Review comments" permission ("Reviewer" '
-                    u'or "Manager") can approve comments to make them '
-                    u'visible to the public. If you want to enable a '
-                    u'custom comment workflow, you have to go to the '
-                    u'types control panel.',
+            "help_moderation_enabled",
+            default='If selected, comments will enter a "Pending" state '
+            "in which they are invisible to the public. A user "
+            'with the "Review comments" permission ("Reviewer" '
+            'or "Manager") can approve comments to make them '
+            "visible to the public. If you want to enable a "
+            "custom comment workflow, you have to go to the "
+            "types control panel.",
         ),
         required=False,
         default=False,
     )
 
     edit_comment_enabled = schema.Bool(
-        title=_(u'label_edit_comment_enabled',
-                default='Enable editing of comments'),
-        description=_(u'help_edit_comment_enabled',
-                      default=u'If selected, supports editing '
-                      'of comments for users with the "Edit comments" '
-                      'permission.'),
+        title=_("label_edit_comment_enabled", default="Enable editing of comments"),
+        description=_(
+            "help_edit_comment_enabled",
+            default="If selected, supports editing "
+            'of comments for users with the "Edit comments" '
+            "permission.",
+        ),
         required=False,
         default=False,
     )
 
     delete_own_comment_enabled = schema.Bool(
-        title=_(u'label_delete_own_comment_enabled',
-                default='Enable deleting own comments'),
-        description=_(u'help_delete_own_comment_enabled',
-                      default=u'If selected, supports deleting '
-                      'of own comments for users with the '
-                      '"Delete own comments" permission.'),
+        title=_(
+            "label_delete_own_comment_enabled", default="Enable deleting own comments"
+        ),
+        description=_(
+            "help_delete_own_comment_enabled",
+            default="If selected, supports deleting "
+            "of own comments for users with the "
+            '"Delete own comments" permission.',
+        ),
         required=False,
         default=False,
     )
 
     text_transform = schema.Choice(
-        title=_(u'label_text_transform',
-                default='Comment text transform'),
+        title=_("label_text_transform", default="Comment text transform"),
         description=_(
-            u'help_text_transform',
-            default=u'Use this setting to choose if the comment text '
-                    u'should be transformed in any way. You can choose '
-                    u'between "Plain text" and "Intelligent text". '
-                    u'"Intelligent text" converts plain text into HTML '
-                    u'where line breaks and indentation is preserved, '
-                    u'and web and email addresses are made into '
-                    u'clickable links.'),
+            "help_text_transform",
+            default="Use this setting to choose if the comment text "
+            "should be transformed in any way. You can choose "
+            'between "Plain text" and "Intelligent text". '
+            '"Intelligent text" converts plain text into HTML '
+            "where line breaks and indentation is preserved, "
+            "and web and email addresses are made into "
+            "clickable links.",
+        ),
         required=True,
-        default='text/plain',
-        vocabulary='plone.app.discussion.vocabularies.TextTransformVocabulary',
+        default="text/plain",
+        vocabulary="plone.app.discussion.vocabularies.TextTransformVocabulary",
     )
 
     captcha = schema.Choice(
-        title=_(u'label_captcha',
-                default='Captcha'),
+        title=_("label_captcha", default="Captcha"),
         description=_(
-            u'help_captcha',
-            default=u'Use this setting to enable or disable Captcha '
-                    u'validation for comments. Install '
-                    u'plone.formwidget.captcha, '
-                    u'plone.formwidget.recaptcha, collective.akismet, or '
-                    u'collective.z3cform.norobots if there are no options '
-                    u'available.'),
+            "help_captcha",
+            default="Use this setting to enable or disable Captcha "
+            "validation for comments. Install "
+            "plone.formwidget.captcha, "
+            "plone.formwidget.recaptcha, collective.akismet, or "
+            "collective.z3cform.norobots if there are no options "
+            "available.",
+        ),
         required=True,
-        default='disabled',
-        vocabulary='plone.app.discussion.vocabularies.CaptchaVocabulary',
+        default="disabled",
+        vocabulary="plone.app.discussion.vocabularies.CaptchaVocabulary",
     )
 
     show_commenter_image = schema.Bool(
-        title=_(u'label_show_commenter_image',
-                default=u'Show commenter image'),
+        title=_("label_show_commenter_image", default="Show commenter image"),
         description=_(
-            u'help_show_commenter_image',
-            default=u'If selected, an image of the user is shown next to '
-                    u'the comment.'),
+            "help_show_commenter_image",
+            default="If selected, an image of the user is shown next to "
+            "the comment.",
+        ),
         required=False,
         default=True,
     )
 
     moderator_notification_enabled = schema.Bool(
-        title=_(u'label_moderator_notification_enabled',
-                default=u'Enable moderator email notification'),
+        title=_(
+            "label_moderator_notification_enabled",
+            default="Enable moderator email notification",
+        ),
         description=_(
-            u'help_moderator_notification_enabled',
-            default=u'If selected, the moderator is notified if a comment '
-                    u'needs attention. The moderator email address can '
-                    u'be set below.'),
+            "help_moderator_notification_enabled",
+            default="If selected, the moderator is notified if a comment "
+            "needs attention. The moderator email address can "
+            "be set below.",
+        ),
         required=False,
         default=False,
     )
 
     moderator_email = schema.ASCIILine(
         title=_(
-            u'label_moderator_email',
-            default=u'Moderator Email Address',
+            "label_moderator_email",
+            default="Moderator Email Address",
         ),
         description=_(
-            u'help_moderator_email',
-            default=u'Address to which moderator notifications '
-                    u'will be sent.'),
+            "help_moderator_email",
+            default="Address to which moderator notifications " "will be sent.",
+        ),
         required=False,
     )
 
     user_notification_enabled = schema.Bool(
         title=_(
-            u'label_user_notification_enabled',
-            default=u'Enable user email notification',
+            "label_user_notification_enabled",
+            default="Enable user email notification",
         ),
         description=_(
-            u'help_user_notification_enabled',
-            default=u'If selected, users can choose to be notified '
-                    u'of new comments by email.'),
+            "help_user_notification_enabled",
+            default="If selected, users can choose to be notified "
+            "of new comments by email.",
+        ),
         required=False,
         default=False,
     )
 
 
 class IDiscussionLayer(Interface):
-    """Request marker installed via browserlayer.xml.
-    """
+    """Request marker installed via browserlayer.xml."""
 
 
 class ICommentingTool(Interface):
@@ -384,54 +385,46 @@ class ICommentingTool(Interface):
     of Plone that had a portal_discussion tool.
     """
 
+
 #
 # Custom events
 #
 
 
 class IDiscussionEvent(IObjectEvent):
-    """ Discussion custom event
-    """
+    """Discussion custom event"""
 
 
 class ICommentAddedEvent(IDiscussionEvent):
-    """ Comment added
-    """
+    """Comment added"""
 
 
 class ICommentModifiedEvent(IDiscussionEvent):
-    """ Comment modified
-    """
+    """Comment modified"""
 
 
 class ICommentRemovedEvent(IDiscussionEvent):
-    """ Comment removed
-    """
+    """Comment removed"""
 
 
 class IReplyAddedEvent(IDiscussionEvent):
-    """ Comment reply added
-    """
+    """Comment reply added"""
 
 
 class IReplyModifiedEvent(IDiscussionEvent):
-    """ Comment reply modified
-    """
+    """Comment reply modified"""
 
 
 class IReplyRemovedEvent(IDiscussionEvent):
-    """ Comment reply removed
-    """
+    """Comment reply removed"""
 
 
 class ICommentPublishedEvent(IDiscussionEvent):
-    """ Notify user on comment publication
-    """
+    """Notify user on comment publication"""
 
 
 class ICommentDeletedEvent(IDiscussionEvent):
-    """ Notify user on comment delete
-    """
+    """Notify user on comment delete"""
 
 
 class ICommentTransitionEvent(IDiscussionEvent):
diff --git a/plone/app/discussion/subscribers.py b/plone/app/discussion/subscribers.py
index 0234c97..6e1b498 100644
--- a/plone/app/discussion/subscribers.py
+++ b/plone/app/discussion/subscribers.py
@@ -1,14 +1,11 @@
-# -*- coding: utf-8 -*-
 from Products.CMFCore.utils import getToolByName
 
 
 def index_object(obj, event):
-    """Index the object when it is added/modified to the conversation.
-    """
+    """Index the object when it is added/modified to the conversation."""
     obj.indexObject()
 
 
 def unindex_object(obj, event):
-    """Unindex the object when it is removed from the conversation.
-    """
+    """Unindex the object when it is removed from the conversation."""
     obj.unindexObject()
diff --git a/plone/app/discussion/subscribers.zcml b/plone/app/discussion/subscribers.zcml
index 85e74e2..a797741 100644
--- a/plone/app/discussion/subscribers.zcml
+++ b/plone/app/discussion/subscribers.zcml
@@ -72,7 +72,7 @@
     <!-- Control panel event subscribers -->
 
     <subscriber
-        for="Products.CMFPlone.interfaces.events.IConfigurationChangedEvent"
+        for="plone.base.interfaces.events.IConfigurationChangedEvent"
         handler=".browser.controlpanel.notify_configuration_changed"
         />
 
diff --git a/plone/app/discussion/testing.py b/plone/app/discussion/testing.py
index 5a4060b..01ea305 100644
--- a/plone/app/discussion/testing.py
+++ b/plone/app/discussion/testing.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 from plone.app.contenttypes.testing import PLONE_APP_CONTENTTYPES_FIXTURE
 from plone.app.discussion.interfaces import IDiscussionSettings
 from plone.app.robotframework.testing import REMOTE_LIBRARY_ROBOT_TESTING
@@ -15,40 +14,43 @@ from zope.component import queryUtility
 
 try:
     import plone.app.collection  # noqa
-    COLLECTION_TYPE = 'Collection'
+
+    COLLECTION_TYPE = "Collection"
 except ImportError:
-    COLLECTION_TYPE = 'Topic'
+    COLLECTION_TYPE = "Topic"
 
 
 class PloneAppDiscussion(PloneSandboxLayer):
 
     defaultBases = (PLONE_APP_CONTENTTYPES_FIXTURE,)
 
-    USER_NAME = 'johndoe'
-    USER_PASSWORD = 'secret'
-    MEMBER_NAME = 'janedoe'
-    MEMBER_PASSWORD = 'secret'
-    USER_WITH_FULLNAME_NAME = 'jim'
-    USER_WITH_FULLNAME_FULLNAME = 'Jim Fulton'
-    USER_WITH_FULLNAME_PASSWORD = 'secret'
-    MANAGER_USER_NAME = 'manager'
-    MANAGER_USER_PASSWORD = 'secret'
-    REVIEWER_NAME = 'reviewer'
-    REVIEWER_PASSWORD = 'secret'
+    USER_NAME = "johndoe"
+    USER_PASSWORD = "secret"
+    MEMBER_NAME = "janedoe"
+    MEMBER_PASSWORD = "secret"
+    USER_WITH_FULLNAME_NAME = "jim"
+    USER_WITH_FULLNAME_FULLNAME = "Jim Fulton"
+    USER_WITH_FULLNAME_PASSWORD = "secret"
+    MANAGER_USER_NAME = "manager"
+    MANAGER_USER_PASSWORD = "secret"
+    REVIEWER_NAME = "reviewer"
+    REVIEWER_PASSWORD = "secret"
 
     def setUpZope(self, app, configurationContext):
         # Load ZCML
         import plone.app.discussion
-        self.loadZCML(package=plone.app.discussion,
-                      context=configurationContext,
-                      )
+
+        self.loadZCML(
+            package=plone.app.discussion,
+            context=configurationContext,
+        )
 
     def setUpPloneSite(self, portal):
         # Install into Plone site using portal_setup
-        applyProfile(portal, 'plone.app.discussion:default')
+        applyProfile(portal, "plone.app.discussion:default")
 
         # Creates some users
-        acl_users = getToolByName(portal, 'acl_users')
+        acl_users = getToolByName(portal, "acl_users")
         acl_users.userFolderAddUser(
             self.USER_NAME,
             self.USER_PASSWORD,
@@ -58,41 +60,42 @@ class PloneAppDiscussion(PloneSandboxLayer):
         acl_users.userFolderAddUser(
             self.MEMBER_NAME,
             self.MEMBER_PASSWORD,
-            ['Member'],
+            ["Member"],
             [],
         )
         acl_users.userFolderAddUser(
             self.USER_WITH_FULLNAME_NAME,
             self.USER_WITH_FULLNAME_PASSWORD,
-            ['Member'],
+            ["Member"],
             [],
         )
         acl_users.userFolderAddUser(
             self.REVIEWER_NAME,
             self.REVIEWER_PASSWORD,
-            ['Member'],
+            ["Member"],
             [],
         )
-        mtool = getToolByName(portal, 'portal_membership', None)
-        gtool = getToolByName(portal, 'portal_groups', None)
-        gtool.addPrincipalToGroup(self.REVIEWER_NAME, 'Reviewers')
-        mtool.addMember('jim', 'Jim', ['Member'], [])
-        mtool.getMemberById('jim').setMemberProperties(
-            {'fullname': 'Jim Fult\xc3\xb8rn'})
+        mtool = getToolByName(portal, "portal_membership", None)
+        gtool = getToolByName(portal, "portal_groups", None)
+        gtool.addPrincipalToGroup(self.REVIEWER_NAME, "Reviewers")
+        mtool.addMember("jim", "Jim", ["Member"], [])
+        mtool.getMemberById("jim").setMemberProperties(
+            {"fullname": "Jim Fult\xc3\xb8rn"}
+        )
 
         acl_users.userFolderAddUser(
             self.MANAGER_USER_NAME,
             self.MANAGER_USER_PASSWORD,
-            ['Manager'],
+            ["Manager"],
             [],
         )
 
         # Add a document
-        setRoles(portal, TEST_USER_ID, ['Manager'])
+        setRoles(portal, TEST_USER_ID, ["Manager"])
         portal.invokeFactory(
-            id='doc1',
-            title='Document 1',
-            type_name='Document',
+            id="doc1",
+            title="Document 1",
+            type_name="Document",
         )
 
 
@@ -112,12 +115,12 @@ class PloneAppDiscussionRobot(PloneAppDiscussion):
 PLONE_APP_DISCUSSION_ROBOT_FIXTURE = PloneAppDiscussionRobot()
 PLONE_APP_DISCUSSION_FIXTURE = PloneAppDiscussion()
 PLONE_APP_DISCUSSION_INTEGRATION_TESTING = IntegrationTesting(
-    bases=(PLONE_APP_DISCUSSION_FIXTURE,),
-    name='PloneAppDiscussion:Integration')
+    bases=(PLONE_APP_DISCUSSION_FIXTURE,), name="PloneAppDiscussion:Integration"
+)
 PLONE_APP_DISCUSSION_FUNCTIONAL_TESTING = FunctionalTesting(
-    bases=(PLONE_APP_DISCUSSION_FIXTURE,),
-    name='PloneAppDiscussion:Functional')
+    bases=(PLONE_APP_DISCUSSION_FIXTURE,), name="PloneAppDiscussion:Functional"
+)
 PLONE_APP_DISCUSSION_ROBOT_TESTING = FunctionalTesting(
     bases=(PLONE_APP_DISCUSSION_ROBOT_FIXTURE,),
-    name='PloneAppDiscussion:Robot',
+    name="PloneAppDiscussion:Robot",
 )
diff --git a/plone/app/discussion/tests/functional_test_comment_review_workflow.txt b/plone/app/discussion/tests/functional_test_comment_review_workflow.txt
index 84d384f..099ce9f 100644
--- a/plone/app/discussion/tests/functional_test_comment_review_workflow.txt
+++ b/plone/app/discussion/tests/functional_test_comment_review_workflow.txt
@@ -252,7 +252,7 @@ Now we can post an anonymous comment.
 
     >>> unprivileged_browser.open(urldoc)
     >>> unprivileged_browser.getControl(name='form.widgets.text').value = "This is an anonymous comment"
-    >>> unprivileged_browser.getControl(name='form.widgets.author_name').value = u'John'
+    >>> unprivileged_browser.getControl(name='form.widgets.author_name').value = 'John'
     >>> unprivileged_browser.getControl(name='form.widgets.author_email').value = 'john@acme.com'
     >>> unprivileged_browser.getControl(name='form.buttons.comment').click()
 
diff --git a/plone/app/discussion/tests/test_catalog.py b/plone/app/discussion/tests/test_catalog.py
index 98abd9f..395f6c2 100644
--- a/plone/app/discussion/tests/test_catalog.py
+++ b/plone/app/discussion/tests/test_catalog.py
@@ -1,9 +1,10 @@
-# -*- coding: utf-8 -*-
 """Test the plone.app.discussion catalog indexes
 """
 from datetime import datetime
 from plone.app.discussion.interfaces import IConversation
-from plone.app.discussion.testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING  # noqa
+from plone.app.discussion.testing import (  # noqa
+    PLONE_APP_DISCUSSION_INTEGRATION_TESTING,
+)
 from plone.app.testing import setRoles
 from plone.app.testing import TEST_USER_ID
 from Products.CMFCore.utils import getToolByName
@@ -21,33 +22,29 @@ class CatalogSetupTest(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
+        self.portal = self.layer["portal"]
 
     def test_catalog_installed(self):
         self.assertTrue(
-            'total_comments' in
-            self.portal.portal_catalog.indexes(),
+            "total_comments" in self.portal.portal_catalog.indexes(),
         )
         self.assertTrue(
-            'commentators' in
-            self.portal.portal_catalog.indexes(),
+            "commentators" in self.portal.portal_catalog.indexes(),
         )
         self.assertTrue(
-            'total_comments' in
-            self.portal.portal_catalog.schema(),
+            "total_comments" in self.portal.portal_catalog.schema(),
         )
         self.assertTrue(
-            'in_response_to' in
-            self.portal.portal_catalog.schema(),
+            "in_response_to" in self.portal.portal_catalog.schema(),
         )
 
     def test_collection_criteria_installed(self):
-        if 'portal_atct' not in self.portal:
+        if "portal_atct" not in self.portal:
             return
         try:
-            self.portal.portal_atct.getIndex('commentators')
-            self.portal.portal_atct.getIndex('total_comments')
-            self.portal.portal_atct.getMetadata('total_comments')
+            self.portal.portal_atct.getIndex("commentators")
+            self.portal.portal_atct.getIndex("total_comments")
+            self.portal.portal_atct.getMetadata("total_comments")
         except AttributeError:
             self.fail()
 
@@ -57,19 +54,19 @@ class ConversationCatalogTest(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
 
         workflow = self.portal.portal_workflow
-        workflow.doActionFor(self.portal.doc1, 'publish')
+        workflow.doActionFor(self.portal.doc1, "publish")
 
-        self.catalog = getToolByName(self.portal, 'portal_catalog')
+        self.catalog = getToolByName(self.portal, "portal_catalog")
         conversation = IConversation(self.portal.doc1)
-        comment1 = createObject('plone.Comment')
-        comment1.title = 'Comment 1'
-        comment1.text = 'Comment text'
-        comment1.creator = 'jim'
-        comment1.author_username = 'Jim'
+        comment1 = createObject("plone.Comment")
+        comment1.title = "Comment 1"
+        comment1.text = "Comment text"
+        comment1.creator = "jim"
+        comment1.author_username = "Jim"
         comment1.creation_date = datetime(2006, 9, 17, 14, 18, 12)
         comment1.modification_date = datetime(2006, 9, 17, 14, 18, 12)
 
@@ -79,9 +76,9 @@ class ConversationCatalogTest(unittest.TestCase):
         brains = self.catalog.searchResults(
             dict(
                 path={
-                    'query': '/'.join(self.portal.doc1.getPhysicalPath()),
+                    "query": "/".join(self.portal.doc1.getPhysicalPath()),
                 },
-                portal_type='Document',
+                portal_type="Document",
             ),
         )
         self.conversation = conversation
@@ -91,54 +88,54 @@ class ConversationCatalogTest(unittest.TestCase):
         self.new_comment1_id = new_comment1_id
 
     def test_total_comments(self):
-        self.assertTrue('total_comments' in self.doc1_brain)
+        self.assertTrue("total_comments" in self.doc1_brain)
         self.assertEqual(self.doc1_brain.total_comments, 1)
 
-        comment2 = createObject('plone.Comment')
-        comment2.title = 'Comment 2'
-        comment2.text = 'Comment text'
+        comment2 = createObject("plone.Comment")
+        comment2.title = "Comment 2"
+        comment2.text = "Comment text"
         new_comment2_id = self.conversation.addComment(comment2)
 
         comment2 = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_comment2_id),
+            f"++conversation++default/{new_comment2_id}",
         )
         comment2.reindexObject()
         brains = self.catalog.searchResults(
             dict(
                 path={
-                    'query': '/'.join(self.portal.doc1.getPhysicalPath()),
+                    "query": "/".join(self.portal.doc1.getPhysicalPath()),
                 },
-                portal_type='Document',
+                portal_type="Document",
             ),
         )
         doc1_brain = brains[0]
         self.assertEqual(doc1_brain.total_comments, 2)
 
     def test_last_comment_date(self):
-        self.assertTrue('last_comment_date' in self.doc1_brain)
+        self.assertTrue("last_comment_date" in self.doc1_brain)
         self.assertEqual(
             self.doc1_brain.last_comment_date,
             datetime(2006, 9, 17, 14, 18, 12),
         )
 
         # Add another comment and check if last comment date is updated.
-        comment2 = createObject('plone.Comment')
-        comment2.title = 'Comment 2'
-        comment2.text = 'Comment text'
+        comment2 = createObject("plone.Comment")
+        comment2.title = "Comment 2"
+        comment2.text = "Comment text"
         comment2.creation_date = datetime(2009, 9, 17, 14, 18, 12)
         comment2.modification_date = datetime(2009, 9, 17, 14, 18, 12)
         new_comment2_id = self.conversation.addComment(comment2)
 
         comment2 = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_comment2_id),
+            f"++conversation++default/{new_comment2_id}",
         )
         comment2.reindexObject()
         brains = self.catalog.searchResults(
             dict(
                 path={
-                    'query': '/'.join(self.portal.doc1.getPhysicalPath()),
+                    "query": "/".join(self.portal.doc1.getPhysicalPath()),
                 },
-                portal_type='Document',
+                portal_type="Document",
             ),
         )
         doc1_brain = brains[0]
@@ -153,9 +150,9 @@ class ConversationCatalogTest(unittest.TestCase):
         brains = self.catalog.searchResults(
             dict(
                 path={
-                    'query': '/'.join(self.portal.doc1.getPhysicalPath()),
+                    "query": "/".join(self.portal.doc1.getPhysicalPath()),
                 },
-                portal_type='Document',
+                portal_type="Document",
             ),
         )
         doc1_brain = brains[0]
@@ -169,44 +166,44 @@ class ConversationCatalogTest(unittest.TestCase):
         brains = self.catalog.searchResults(
             dict(
                 path={
-                    'query': '/'.join(self.portal.doc1.getPhysicalPath()),
+                    "query": "/".join(self.portal.doc1.getPhysicalPath()),
                 },
-                portal_type='Document',
+                portal_type="Document",
             ),
         )
         doc1_brain = brains[0]
         self.assertEqual(doc1_brain.last_comment_date, None)
 
     def test_commentators(self):
-        self.assertTrue('commentators' in self.doc1_brain)
-        self.assertEqual(self.doc1_brain.commentators, ('Jim',))
+        self.assertTrue("commentators" in self.doc1_brain)
+        self.assertEqual(self.doc1_brain.commentators, ("Jim",))
 
         # add another comment with another author
-        comment2 = createObject('plone.Comment')
-        comment2.title = 'Comment 2'
-        comment2.text = 'Comment text'
-        comment2.creator = 'emma'
-        comment2.author_username = 'Emma'
+        comment2 = createObject("plone.Comment")
+        comment2.title = "Comment 2"
+        comment2.text = "Comment text"
+        comment2.creator = "emma"
+        comment2.author_username = "Emma"
         new_comment2_id = self.conversation.addComment(comment2)
 
         comment2 = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_comment2_id),
+            f"++conversation++default/{new_comment2_id}",
         )
         comment2.reindexObject()
 
         brains = self.catalog.searchResults(
             dict(
                 path={
-                    'query': '/'.join(self.portal.doc1.getPhysicalPath()),
+                    "query": "/".join(self.portal.doc1.getPhysicalPath()),
                 },
-                portal_type='Document',
+                portal_type="Document",
             ),
         )
         doc1_brain = brains[0]
 
         self.assertEqual(
             sorted(doc1_brain.commentators),
-            sorted(('Jim', 'Emma')),
+            sorted(("Jim", "Emma")),
         )
 
         # remove one comments
@@ -214,22 +211,22 @@ class ConversationCatalogTest(unittest.TestCase):
         brains = self.catalog.searchResults(
             dict(
                 path={
-                    'query': '/'.join(self.portal.doc1.getPhysicalPath()),
+                    "query": "/".join(self.portal.doc1.getPhysicalPath()),
                 },
-                portal_type='Document',
+                portal_type="Document",
             ),
         )
         doc1_brain = brains[0]
-        self.assertEqual(doc1_brain.commentators, ('Jim',))
+        self.assertEqual(doc1_brain.commentators, ("Jim",))
 
         # remove all comments
         del self.conversation[self.new_comment1_id]
         brains = self.catalog.searchResults(
             dict(
                 path={
-                    'query': '/'.join(self.portal.doc1.getPhysicalPath()),
+                    "query": "/".join(self.portal.doc1.getPhysicalPath()),
                 },
-                portal_type='Document',
+                portal_type="Document",
             ),
         )
         doc1_brain = brains[0]
@@ -239,9 +236,9 @@ class ConversationCatalogTest(unittest.TestCase):
         brains = self.catalog.searchResults(
             dict(
                 path={
-                    'query': '/'.join(self.portal.doc1.getPhysicalPath()),
+                    "query": "/".join(self.portal.doc1.getPhysicalPath()),
                 },
-                portal_type='Discussion Item',
+                portal_type="Discussion Item",
             ),
         )
         comment1_brain = brains[0]
@@ -250,14 +247,14 @@ class ConversationCatalogTest(unittest.TestCase):
         self.assertEqual(comment1_brain.total_comments, None)
 
     def test_dont_index_private_commentators(self):
-        self.comment1.manage_permission('View', roles=tuple())
+        self.comment1.manage_permission("View", roles=tuple())
         self.portal.doc1.reindexObject()
         brains = self.catalog.searchResults(
             dict(
                 path={
-                    'query': '/'.join(self.portal.doc1.getPhysicalPath()),
+                    "query": "/".join(self.portal.doc1.getPhysicalPath()),
                 },
-                portal_type='Document',
+                portal_type="Document",
             ),
         )
         doc1_brain = brains[0]
@@ -269,70 +266,70 @@ class CommentCatalogTest(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
-        self.catalog = getToolByName(self.portal, 'portal_catalog')
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
+        self.catalog = getToolByName(self.portal, "portal_catalog")
 
         conversation = IConversation(self.portal.doc1)
         self.conversation = conversation
 
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'Comment text'
-        comment1.creator = 'jim'
-        comment1.author_name = 'Jim'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Comment text"
+        comment1.creator = "jim"
+        comment1.author_name = "Jim"
         new_comment1_id = conversation.addComment(comment1)
         self.comment_id = new_comment1_id
 
         # Comment brain
         self.comment = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_comment1_id),
+            f"++conversation++default/{new_comment1_id}",
         )
         brains = self.catalog.searchResults(
             dict(
                 path={
-                    'query': '/'.join(self.comment.getPhysicalPath()),
+                    "query": "/".join(self.comment.getPhysicalPath()),
                 },
             ),
         )
         self.comment_brain = brains[0]
 
     def test_title(self):
-        self.assertEqual(self.comment_brain.Title, 'Jim on Document 1')
+        self.assertEqual(self.comment_brain.Title, "Jim on Document 1")
 
     def test_no_name_title(self):
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         cid = self.conversation.addComment(comment)
 
         # Comment brain
         comment = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(cid),
+            f"++conversation++default/{cid}",
         )
         brains = self.catalog.searchResults(
             dict(
                 path={
-                    'query': '/'.join(comment.getPhysicalPath()),
+                    "query": "/".join(comment.getPhysicalPath()),
                 },
             ),
         )
         comment_brain = brains[0]
-        self.assertEqual(comment_brain.Title, 'Anonymous on Document 1')
+        self.assertEqual(comment_brain.Title, "Anonymous on Document 1")
 
     def test_type(self):
-        self.assertEqual(self.comment_brain.portal_type, 'Discussion Item')
-        self.assertEqual(self.comment_brain.Type, 'Comment')
+        self.assertEqual(self.comment_brain.portal_type, "Discussion Item")
+        self.assertEqual(self.comment_brain.Type, "Comment")
 
     def test_review_state(self):
-        self.assertEqual(self.comment_brain.review_state, 'published')
+        self.assertEqual(self.comment_brain.review_state, "published")
 
     def test_creator(self):
-        self.assertEqual(self.comment_brain.Creator, 'jim')
+        self.assertEqual(self.comment_brain.Creator, "jim")
 
     def test_in_response_to(self):
         """Make sure in_response_to returns the title or id of the content
-           object the comment was added to.
+        object the comment was added to.
         """
-        self.assertEqual(self.comment_brain.in_response_to, 'Document 1')
+        self.assertEqual(self.comment_brain.in_response_to, "Document 1")
 
     def test_add_comment(self):
         self.assertTrue(self.comment_brain)
@@ -344,7 +341,7 @@ class CommentCatalogTest(unittest.TestCase):
         brains = self.catalog.searchResults(
             dict(
                 path={
-                    'query': '/'.join(self.comment.getPhysicalPath()),
+                    "query": "/".join(self.comment.getPhysicalPath()),
                 },
             ),
         )
@@ -352,54 +349,54 @@ class CommentCatalogTest(unittest.TestCase):
 
     def test_reindex_comment(self):
         # Make sure a comment is reindexed on the catalog when is modified
-        self.comment.text = 'Another text'
+        self.comment.text = "Another text"
         notify(ObjectModifiedEvent(self.comment))
-        brains = self.catalog.searchResults(SearchableText='Another text')
+        brains = self.catalog.searchResults(SearchableText="Another text")
         self.assertEqual(len(brains), 1)
 
     def test_remove_comments_when_content_object_is_removed(self):
         """Make sure all comments are removed from the catalog, if the content
-           object is removed.
+        object is removed.
         """
-        brains = self.catalog.searchResults({'portal_type': 'Discussion Item'})
+        brains = self.catalog.searchResults({"portal_type": "Discussion Item"})
         self.assertEqual(len(brains), 1)
-        self.portal.manage_delObjects(['doc1'])
-        brains = self.catalog.searchResults({'portal_type': 'Discussion Item'})
+        self.portal.manage_delObjects(["doc1"])
+        brains = self.catalog.searchResults({"portal_type": "Discussion Item"})
         self.assertEqual(len(brains), 0)
 
     def test_move_comments_when_content_object_is_moved(self):
         # Create two folders and a content object with a comment
         self.portal.invokeFactory(
-            id='folder1',
-            title='Folder 1',
-            type_name='Folder',
+            id="folder1",
+            title="Folder 1",
+            type_name="Folder",
         )
         self.portal.invokeFactory(
-            id='folder2',
-            title='Folder 2',
-            type_name='Folder',
+            id="folder2",
+            title="Folder 2",
+            type_name="Folder",
         )
         self.portal.folder1.invokeFactory(
-            id='moveme',
-            title='Move Me',
-            type_name='Document',
+            id="moveme",
+            title="Move Me",
+            type_name="Document",
         )
         conversation = IConversation(self.portal.folder1.moveme)
-        comment = createObject('plone.Comment')
+        comment = createObject("plone.Comment")
         comment_id = conversation.addComment(comment)
         # We need to commit here so that _p_jar isn't None and move will work
         transaction.savepoint(optimistic=True)
 
         # Move moveme from folder1 to folder2
-        cp = self.portal.folder1.manage_cutObjects(ids=('moveme',))
+        cp = self.portal.folder1.manage_cutObjects(ids=("moveme",))
         self.portal.folder2.manage_pasteObjects(cp)
 
         # Make sure no old comment brains are
         brains = self.catalog.searchResults(
             dict(
-                portal_type='Discussion Item',
+                portal_type="Discussion Item",
                 path={
-                    'query': '/'.join(self.portal.folder1.getPhysicalPath()),
+                    "query": "/".join(self.portal.folder1.getPhysicalPath()),
                 },
             ),
         )
@@ -407,61 +404,60 @@ class CommentCatalogTest(unittest.TestCase):
 
         brains = self.catalog.searchResults(
             dict(
-                portal_type='Discussion Item',
+                portal_type="Discussion Item",
                 path={
-                    'query': '/'.join(self.portal.folder2.getPhysicalPath()),
+                    "query": "/".join(self.portal.folder2.getPhysicalPath()),
                 },
             ),
         )
         self.assertEqual(len(brains), 1)
         self.assertEqual(
             brains[0].getPath(),
-            '/plone/folder2/moveme/++conversation++default/' +
-            str(comment_id),
+            "/plone/folder2/moveme/++conversation++default/" + str(comment_id),
         )
 
     def test_move_upper_level_folder(self):
         # create a folder with a nested structure
         self.portal.invokeFactory(
-            id='sourcefolder',
-            title='Source Folder',
-            type_name='Folder',
+            id="sourcefolder",
+            title="Source Folder",
+            type_name="Folder",
         )
         self.portal.sourcefolder.invokeFactory(
-            id='moveme',
-            title='Move Me',
-            type_name='Folder',
+            id="moveme",
+            title="Move Me",
+            type_name="Folder",
         )
         self.portal.sourcefolder.moveme.invokeFactory(
-            id='mydocument',
-            title='My Document',
-            type_name='Folder',
+            id="mydocument",
+            title="My Document",
+            type_name="Folder",
         )
         self.portal.invokeFactory(
-            id='targetfolder',
-            title='Target Folder',
-            type_name='Folder',
+            id="targetfolder",
+            title="Target Folder",
+            type_name="Folder",
         )
 
         # create comment on my-document
         conversation = IConversation(
             self.portal.sourcefolder.moveme.mydocument,
         )
-        comment = createObject('plone.Comment')
+        comment = createObject("plone.Comment")
         comment_id = conversation.addComment(comment)
 
         # We need to commit here so that _p_jar isn't None and move will work
         transaction.savepoint(optimistic=True)
 
         # Move moveme from folder1 to folder2
-        cp = self.portal.sourcefolder.manage_cutObjects(ids=('moveme',))
+        cp = self.portal.sourcefolder.manage_cutObjects(ids=("moveme",))
         self.portal.targetfolder.manage_pasteObjects(cp)
 
         # Make sure no old comment brains are left
         brains = self.catalog.searchResults(
             dict(
-                portal_type='Discussion Item',
-                path={'query': '/plone/sourcefolder/moveme'},
+                portal_type="Discussion Item",
+                path={"query": "/plone/sourcefolder/moveme"},
             ),
         )
         self.assertEqual(len(brains), 0)
@@ -469,49 +465,47 @@ class CommentCatalogTest(unittest.TestCase):
         # make sure comments are correctly index on the target
         brains = self.catalog.searchResults(
             dict(
-                portal_type='Discussion Item',
-                path={'query': '/plone/targetfolder/moveme'},
+                portal_type="Discussion Item",
+                path={"query": "/plone/targetfolder/moveme"},
             ),
         )
         self.assertEqual(len(brains), 1)
         self.assertEqual(
             brains[0].getPath(),
-            '/plone/targetfolder/moveme/mydocument/++conversation++default/' +
-            str(comment_id),
+            "/plone/targetfolder/moveme/mydocument/++conversation++default/"
+            + str(comment_id),
         )
 
     def test_update_comments_when_content_object_is_renamed(self):
         # We need to commit here so that _p_jar isn't None and move will work
         transaction.savepoint(optimistic=True)
 
-        self.portal.manage_renameObject('doc1', 'doc2')
+        self.portal.manage_renameObject("doc1", "doc2")
 
         brains = self.catalog.searchResults(
-            portal_type='Discussion Item',
+            portal_type="Discussion Item",
         )
         self.assertEqual(len(brains), 1)
         self.assertEqual(
             brains[0].getPath(),
-            '/plone/doc2/++conversation++default/' +
-            str(self.comment_id),
+            "/plone/doc2/++conversation++default/" + str(self.comment_id),
         )
 
     def test_clear_and_rebuild_catalog(self):
-        brains = self.catalog.searchResults({'portal_type': 'Discussion Item'})
+        brains = self.catalog.searchResults({"portal_type": "Discussion Item"})
         self.assertTrue(brains)
 
         # Clear and rebuild catalog
         self.catalog.clearFindAndRebuild()
 
         # Check if comment is still there
-        brains = self.catalog.searchResults({'portal_type': 'Discussion Item'})
+        brains = self.catalog.searchResults({"portal_type": "Discussion Item"})
         self.assertTrue(brains)
         comment_brain = brains[0]
-        self.assertEqual(comment_brain.Title, u'Jim on Document 1')
+        self.assertEqual(comment_brain.Title, "Jim on Document 1")
         self.assertEqual(
             comment_brain.getPath(),
-            '/plone/doc1/++conversation++default/' +
-            str(self.comment_id),
+            "/plone/doc1/++conversation++default/" + str(self.comment_id),
         )
 
     def test_clear_and_rebuild_catalog_for_nested_comments(self):
@@ -526,25 +520,25 @@ class CommentCatalogTest(unittest.TestCase):
         # +- Comment 2
         #    +- Comment 2_1
 
-        comment1_1 = createObject('plone.Comment')
-        comment1_1.title = 'Re: Comment 1'
-        comment1_1.text = 'Comment text'
+        comment1_1 = createObject("plone.Comment")
+        comment1_1.title = "Re: Comment 1"
+        comment1_1.text = "Comment text"
 
-        comment1_1_1 = createObject('plone.Comment')
-        comment1_1_1.title = 'Re: Re: Comment 1'
-        comment1_1_1.text = 'Comment text'
+        comment1_1_1 = createObject("plone.Comment")
+        comment1_1_1.title = "Re: Re: Comment 1"
+        comment1_1_1.text = "Comment text"
 
-        comment1_2 = createObject('plone.Comment')
-        comment1_2.title = 'Re: Comment 1 (2)'
-        comment1_2.text = 'Comment text'
+        comment1_2 = createObject("plone.Comment")
+        comment1_2.title = "Re: Comment 1 (2)"
+        comment1_2.text = "Comment text"
 
-        comment2 = createObject('plone.Comment')
-        comment2.title = 'Comment 2'
-        comment2.text = 'Comment text'
+        comment2 = createObject("plone.Comment")
+        comment2.title = "Comment 2"
+        comment2.text = "Comment text"
 
-        comment2_1 = createObject('plone.Comment')
-        comment2_1.title = 'Re: Comment 2'
-        comment2_1.text = 'Comment text'
+        comment2_1 = createObject("plone.Comment")
+        comment2_1.title = "Re: Comment 2"
+        comment2_1.text = "Comment text"
 
         # Create the nested comment structure
         new_id_1 = self.conversation.addComment(self.comment)
@@ -566,7 +560,7 @@ class CommentCatalogTest(unittest.TestCase):
         self.catalog.clearFindAndRebuild()
 
         # Check if comments are still there
-        brains = self.catalog.searchResults({'portal_type': 'Discussion Item'})
+        brains = self.catalog.searchResults({"portal_type": "Discussion Item"})
         self.assertTrue(brains)
         self.assertEqual(len(brains), 6)
 
@@ -576,19 +570,19 @@ class NoConversationCatalogTest(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
 
-        self.catalog = getToolByName(self.portal, 'portal_catalog')
+        self.catalog = getToolByName(self.portal, "portal_catalog")
 
         conversation = IConversation(self.portal.doc1)
 
         brains = self.catalog.searchResults(
             dict(
                 path={
-                    'query': '/'.join(self.portal.doc1.getPhysicalPath()),
+                    "query": "/".join(self.portal.doc1.getPhysicalPath()),
                 },
-                portal_type='Document',
+                portal_type="Document",
             ),
         )
         self.conversation = conversation
@@ -596,11 +590,10 @@ class NoConversationCatalogTest(unittest.TestCase):
         self.doc1_brain = brains[0]
 
     def test_total_comments(self):
-        self.assertTrue('total_comments' in self.doc1_brain)
+        self.assertTrue("total_comments" in self.doc1_brain)
         self.assertEqual(self.doc1_brain.total_comments, 0)
 
         # Make sure no conversation has been created
         self.assertTrue(
-            'plone.app.discussion:conversation' not in
-            IAnnotations(self.portal.doc1),
+            "plone.app.discussion:conversation" not in IAnnotations(self.portal.doc1),
         )
diff --git a/plone/app/discussion/tests/test_comment.py b/plone/app/discussion/tests/test_comment.py
index f5f726c..17bcb64 100644
--- a/plone/app/discussion/tests/test_comment.py
+++ b/plone/app/discussion/tests/test_comment.py
@@ -1,9 +1,8 @@
-# -*- coding: utf-8 -*-
 from plone.app.discussion.browser.comment import View
 from plone.app.discussion.interfaces import IComment
 from plone.app.discussion.interfaces import IConversation
 from plone.app.discussion.interfaces import IReplies
-from plone.app.discussion.testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING  # noqa
+from plone.app.discussion.testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 from plone.app.testing import setRoles
 from plone.app.testing import TEST_USER_ID
 from Products.CMFCore.utils import getToolByName
@@ -12,11 +11,10 @@ from zope.component import getMultiAdapter
 
 import datetime
 import logging
-import six
 import unittest
 
 
-logger = logging.getLogger('plone.app.discussion.tests')
+logger = logging.getLogger("plone.app.discussion.tests")
 logger.addHandler(logging.StreamHandler())
 
 
@@ -25,30 +23,30 @@ class CommentTest(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        self.request = self.layer['request']
+        self.portal = self.layer["portal"]
+        self.request = self.layer["request"]
 
         workflow = self.portal.portal_workflow
-        workflow.doActionFor(self.portal.doc1, 'publish')
+        workflow.doActionFor(self.portal.doc1, "publish")
 
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
-        self.catalog = getToolByName(self.portal, 'portal_catalog')
-        self.document_brain = self.catalog.searchResults(
-            portal_type='Document')[0]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
+        self.catalog = getToolByName(self.portal, "portal_catalog")
+        self.document_brain = self.catalog.searchResults(portal_type="Document")[0]
 
     def test_factory(self):
-        comment1 = createObject('plone.Comment')
+        comment1 = createObject("plone.Comment")
         self.assertTrue(IComment.providedBy(comment1))
 
     def test_UTCDates(self):
-        utc_to_local_diff = \
-            datetime.datetime.now() - datetime.datetime.utcnow()
+        utc_to_local_diff = datetime.datetime.now() - datetime.datetime.utcnow()
         utc_to_local_diff = abs(utc_to_local_diff.seconds)
         if utc_to_local_diff < 60:
-            logger.warning('Your computer is living in a timezone where local '
-                           'time equals utc time. Some potential errors can '
-                           'get hidden by that')
-        comment1 = createObject('plone.Comment')
+            logger.warning(
+                "Your computer is living in a timezone where local "
+                "time equals utc time. Some potential errors can "
+                "get hidden by that"
+            )
+        comment1 = createObject("plone.Comment")
         local_utc = datetime.datetime.utcnow()
         for date in (comment1.creation_date, comment1.modification_date):
             difference = abs(date - local_utc)
@@ -58,171 +56,163 @@ class CommentTest(unittest.TestCase):
             self.assertFalse(difference // 10)
 
     def test_id(self):
-        comment1 = createObject('plone.Comment')
+        comment1 = createObject("plone.Comment")
         comment1.comment_id = 123
-        self.assertEqual('123', comment1.id)
-        self.assertEqual('123', comment1.getId())
-        self.assertEqual(u'123', comment1.__name__)
+        self.assertEqual("123", comment1.id)
+        self.assertEqual("123", comment1.getId())
+        self.assertEqual("123", comment1.__name__)
 
     def test_uid(self):
         conversation = IConversation(self.portal.doc1)
-        comment1 = createObject('plone.Comment')
+        comment1 = createObject("plone.Comment")
         conversation.addComment(comment1)
         comment_brain = self.catalog.searchResults(
-            portal_type='Discussion Item',
+            portal_type="Discussion Item",
         )[0]
         self.assertTrue(comment_brain.UID)
 
     def test_uid_is_unique(self):
         conversation = IConversation(self.portal.doc1)
-        comment1 = createObject('plone.Comment')
+        comment1 = createObject("plone.Comment")
         conversation.addComment(comment1)
-        comment2 = createObject('plone.Comment')
+        comment2 = createObject("plone.Comment")
         conversation.addComment(comment2)
         brains = self.catalog.searchResults(
-            portal_type='Discussion Item',
+            portal_type="Discussion Item",
         )
         self.assertNotEqual(brains[0].UID, brains[1].UID)
 
     def test_comment_uid_differs_from_content_uid(self):
         conversation = IConversation(self.portal.doc1)
-        comment1 = createObject('plone.Comment')
+        comment1 = createObject("plone.Comment")
         conversation.addComment(comment1)
         comment_brain = self.catalog.searchResults(
-            portal_type='Discussion Item',
+            portal_type="Discussion Item",
         )[0]
         self.assertNotEqual(self.document_brain.UID, comment_brain.UID)
 
     def test_title(self):
         conversation = IConversation(self.portal.doc1)
-        comment1 = createObject('plone.Comment')
-        comment1.author_name = 'Jim Fulton'
+        comment1 = createObject("plone.Comment")
+        comment1.author_name = "Jim Fulton"
         conversation.addComment(comment1)
-        self.assertEqual('Jim Fulton on Document 1', comment1.Title())
+        self.assertEqual("Jim Fulton on Document 1", comment1.Title())
 
     def test_no_name_title(self):
         conversation = IConversation(self.portal.doc1)
-        comment1 = createObject('plone.Comment')
+        comment1 = createObject("plone.Comment")
         conversation.addComment(comment1)
-        self.assertEqual('Anonymous on Document 1', comment1.Title())
+        self.assertEqual("Anonymous on Document 1", comment1.Title())
 
     def test_title_special_characters(self):
         self.portal.invokeFactory(
-            id='doc_sp_chars',
-            title=u'Document äüö',
-            type_name='Document',
+            id="doc_sp_chars",
+            title="Document äüö",
+            type_name="Document",
         )
         conversation = IConversation(self.portal.doc_sp_chars)
-        comment1 = createObject('plone.Comment')
-        comment1.author_name = u'Tarek Ziadé'
+        comment1 = createObject("plone.Comment")
+        comment1.author_name = "Tarek Ziadé"
         conversation.addComment(comment1)
-        self.assertEqual(u'Tarek Ziadé on Document äüö', comment1.Title())
+        self.assertEqual("Tarek Ziadé on Document äüö", comment1.Title())
 
     def test_title_special_characters_utf8(self):
         self.portal.invokeFactory(
-            id='doc_sp_chars_utf8',
-            title='Document ëïû',
-            type_name='Document',
+            id="doc_sp_chars_utf8",
+            title="Document ëïû",
+            type_name="Document",
         )
         conversation = IConversation(self.portal.doc_sp_chars_utf8)
-        comment1 = createObject('plone.Comment')
-        comment1.author_name = 'Hüüb Bôûmä'
+        comment1 = createObject("plone.Comment")
+        comment1.author_name = "Hüüb Bôûmä"
         conversation.addComment(comment1)
-        self.assertEqual(u'Hüüb Bôûmä on Document ëïû', comment1.Title())
+        self.assertEqual("Hüüb Bôûmä on Document ëïû", comment1.Title())
 
     def test_creator(self):
-        comment1 = createObject('plone.Comment')
-        comment1.creator = 'jim'
-        self.assertEqual('jim', comment1.Creator())
+        comment1 = createObject("plone.Comment")
+        comment1.creator = "jim"
+        self.assertEqual("jim", comment1.Creator())
 
     def test_creator_author_name(self):
-        comment1 = createObject('plone.Comment')
-        comment1.author_name = 'joey'
-        self.assertEqual('joey', comment1.Creator())
+        comment1 = createObject("plone.Comment")
+        comment1.author_name = "joey"
+        self.assertEqual("joey", comment1.Creator())
 
     def test_owner(self):
-        comment1 = createObject('plone.Comment')
-        self.assertEqual((['plone', 'acl_users'], TEST_USER_ID),
-                         comment1.getOwnerTuple())
+        comment1 = createObject("plone.Comment")
+        self.assertEqual(
+            (["plone", "acl_users"], TEST_USER_ID), comment1.getOwnerTuple()
+        )
 
     def test_type(self):
-        comment1 = createObject('plone.Comment')
-        self.assertEqual(comment1.Type(), 'Comment')
+        comment1 = createObject("plone.Comment")
+        self.assertEqual(comment1.Type(), "Comment")
 
     def test_mime_type(self):
-        comment1 = createObject('plone.Comment')
-        self.assertEqual(comment1.mime_type, 'text/plain')
+        comment1 = createObject("plone.Comment")
+        self.assertEqual(comment1.mime_type, "text/plain")
 
     def test_getText(self):
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'First paragraph\n\nSecond_paragraph'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "First paragraph\n\nSecond_paragraph"
         self.assertEqual(
-            ''.join(comment1.getText().split()),
-            '<p>Firstparagraph<br><br>Second_paragraph</p>',
+            "".join(comment1.getText().split()),
+            "<p>Firstparagraph<br><br>Second_paragraph</p>",
         )
 
     def test_getText_escapes_HTML(self):
-        comment1 = createObject('plone.Comment')
-        comment1.text = '<b>Got HTML?</b>'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "<b>Got HTML?</b>"
         self.assertEqual(
             comment1.getText(),
-            '<p>&lt;b&gt;Got HTML?&lt;/b&gt;</p>',
+            "<p>&lt;b&gt;Got HTML?&lt;/b&gt;</p>",
         )
 
     def test_getText_with_non_ascii_characters(self):
-        comment1 = createObject('plone.Comment')
-        comment1.text = u'Umlaute sind ä, ö und ü.'
-        out = b'<p>Umlaute sind \xc3\xa4, \xc3\xb6 und \xc3\xbc.</p>'
-        if six.PY2:
-            self.assertEqual(
-                comment1.getText(),
-                out)
-        else:
-            self.assertEqual(
-                comment1.getText(),
-                out.decode('utf8'))
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Umlaute sind ä, ö und ü."
+        out = b"<p>Umlaute sind \xc3\xa4, \xc3\xb6 und \xc3\xbc.</p>"
+        self.assertEqual(comment1.getText(), out.decode("utf8"))
 
     def test_getText_doesnt_link(self):
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'Go to http://www.plone.org'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Go to http://www.plone.org"
         self.assertEqual(
             comment1.getText(),
-            '<p>Go to http://www.plone.org</p>',
+            "<p>Go to http://www.plone.org</p>",
         )
 
     def test_getText_uses_comment_mime_type(self):
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'Go to http://www.plone.org'
-        comment1.mime_type = 'text/x-web-intelligent'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Go to http://www.plone.org"
+        comment1.mime_type = "text/x-web-intelligent"
         self.assertEqual(
             comment1.getText(),
-            'Go to <a href="http://www.plone.org" ' +
-            'rel="nofollow">http://www.plone.org</a>',
+            'Go to <a href="http://www.plone.org" '
+            + 'rel="nofollow">http://www.plone.org</a>',
         )
 
     def test_getText_uses_comment_mime_type_html(self):
-        comment1 = createObject('plone.Comment')
+        comment1 = createObject("plone.Comment")
         comment1.text = 'Go to <a href="http://www.plone.org">plone.org</a>'
-        comment1.mime_type = 'text/html'
+        comment1.mime_type = "text/html"
         self.assertEqual(
             comment1.getText(),
             'Go to <a href="http://www.plone.org">plone.org</a>',
         )
 
     def test_getText_w_custom_targetMimetype(self):
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'para'
-        self.assertEqual(comment1.getText(targetMimetype='text/plain'), 'para')
+        comment1 = createObject("plone.Comment")
+        comment1.text = "para"
+        self.assertEqual(comment1.getText(targetMimetype="text/plain"), "para")
 
     def test_getText_invalid_transformation_raises_error(self):
         conversation = IConversation(self.portal.doc1)
-        comment1 = createObject('plone.Comment')
-        comment1.mime_type = 'text/x-html-safe'
-        comment1.text = 'para'
+        comment1 = createObject("plone.Comment")
+        comment1.mime_type = "text/x-html-safe"
+        comment1.text = "para"
         conversation.addComment(comment1)
-        self.assertEqual(
-            comment1.getText(targetMimetype='text/html'),
-            'para')
+        self.assertEqual(comment1.getText(targetMimetype="text/html"), "para")
 
     def test_traversal(self):
         # make sure comments are traversable, have an id, absolute_url and
@@ -230,26 +220,29 @@ class CommentTest(unittest.TestCase):
 
         conversation = IConversation(self.portal.doc1)
 
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'Comment text'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Comment text"
 
         new_comment1_id = conversation.addComment(comment1)
 
         comment = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_comment1_id),
+            f"++conversation++default/{new_comment1_id}",
         )
         self.assertTrue(IComment.providedBy(comment))
 
         self.assertEqual(
             (
-                '', 'plone', 'doc1', '++conversation++default',
+                "",
+                "plone",
+                "doc1",
+                "++conversation++default",
                 str(new_comment1_id),
             ),
             comment.getPhysicalPath(),
         )
         self.assertEqual(
-            'http://nohost/plone/doc1/++conversation++default/' +
-            str(new_comment1_id), comment.absolute_url(),
+            "http://nohost/plone/doc1/++conversation++default/" + str(new_comment1_id),
+            comment.absolute_url(),
         )
 
     def test_view_blob_types(self):
@@ -258,68 +251,67 @@ class CommentTest(unittest.TestCase):
         version of the url with a /view in it.
         """
         self.portal.invokeFactory(
-            id='image1',
-            title='Image',
-            type_name='Image',
+            id="image1",
+            title="Image",
+            type_name="Image",
         )
         conversation = IConversation(self.portal.image1)
 
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'Comment text'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Comment text"
         new_comment1_id = conversation.addComment(comment1)
         comment = self.portal.image1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_comment1_id),
+            f"++conversation++default/{new_comment1_id}",
         )
 
         view = View(comment, self.request)
         View.__call__(view)
         response = self.request.response
-        self.assertIn('/view', response.headers['location'])
+        self.assertIn("/view", response.headers["location"])
 
     def test_workflow(self):
-        """Basic test for the 'comment_review_workflow'
-        """
+        """Basic test for the 'comment_review_workflow'"""
         self.portal.portal_workflow.setChainForPortalTypes(
-            ('Discussion Item',),
-            ('comment_review_workflow,'),
+            ("Discussion Item",),
+            ("comment_review_workflow,"),
         )
 
         conversation = IConversation(self.portal.doc1)
-        comment1 = createObject('plone.Comment')
+        comment1 = createObject("plone.Comment")
         new_comment1_id = conversation.addComment(comment1)
 
         comment = conversation[new_comment1_id]
 
         # Make sure comments use the 'comment_review_workflow'
         chain = self.portal.portal_workflow.getChainFor(comment)
-        self.assertEqual(('comment_review_workflow',), chain)
+        self.assertEqual(("comment_review_workflow",), chain)
 
         # Ensure the initial state was entered and recorded
         self.assertEqual(
             1,
-            len(comment.workflow_history['comment_review_workflow']),
+            len(comment.workflow_history["comment_review_workflow"]),
         )
         self.assertEqual(
             None,
-            comment.workflow_history['comment_review_workflow'][0]['action'],
+            comment.workflow_history["comment_review_workflow"][0]["action"],
         )
         self.assertEqual(
-            'pending',
-            self.portal.portal_workflow.getInfoFor(comment, 'review_state'),
+            "pending",
+            self.portal.portal_workflow.getInfoFor(comment, "review_state"),
         )
 
     def test_fti(self):
         # test that we can look up an FTI for Discussion Item
 
         self.assertIn(
-            'Discussion Item',
+            "Discussion Item",
             self.portal.portal_types.objectIds(),
         )
 
-        comment1 = createObject('plone.Comment')
+        comment1 = createObject("plone.Comment")
 
         fti = self.portal.portal_types.getTypeInfo(comment1)
-        self.assertEqual('Discussion Item', fti.getTypeInfo(comment1).getId())
+        self.assertEqual("Discussion Item", fti.getTypeInfo(comment1).getId())
 
     def test_view(self):
         # make sure that the comment view is there and redirects to the right
@@ -330,21 +322,21 @@ class CommentTest(unittest.TestCase):
         conversation = IConversation(self.portal.doc1)
 
         # Create a comment
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'Comment text'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Comment text"
 
         # Add comment to the conversation
         new_comment1_id = conversation.addComment(comment1)
 
         comment = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_comment1_id),
+            f"++conversation++default/{new_comment1_id}",
         )
 
         # make sure the view is there
         self.assertTrue(
             getMultiAdapter(
                 (comment, self.request),
-                name='view',
+                name="view",
             ),
         )
 
@@ -362,11 +354,11 @@ class RepliesTest(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
 
         workflow = self.portal.portal_workflow
-        workflow.doActionFor(self.portal.doc1, 'publish')
+        workflow.doActionFor(self.portal.doc1, "publish")
 
     def test_add_comment(self):
         # Add comments to a CommentReplies adapter
@@ -378,16 +370,16 @@ class RepliesTest(unittest.TestCase):
         # Add a comment to the conversation
         replies = IReplies(conversation)
 
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         new_id = replies.addComment(comment)
         comment = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id),
+            f"++conversation++default/{new_id}",
         )
 
         # Add a reply to the CommentReplies adapter of the first comment
-        re_comment = createObject('plone.Comment')
-        re_comment.text = 'Comment text'
+        re_comment = createObject("plone.Comment")
+        re_comment.text = "Comment text"
 
         replies = IReplies(comment)
 
@@ -415,16 +407,16 @@ class RepliesTest(unittest.TestCase):
         # Add a comment to the conversation
         replies = IReplies(conversation)
 
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         new_id = replies.addComment(comment)
         comment = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id),
+            f"++conversation++default/{new_id}",
         )
 
         # Add a reply to the CommentReplies adapter of the first comment
-        re_comment = createObject('plone.Comment')
-        re_comment.text = 'Comment text'
+        re_comment = createObject("plone.Comment")
+        re_comment.text = "Comment text"
 
         replies = IReplies(comment)
 
@@ -446,83 +438,86 @@ class RepliesTest(unittest.TestCase):
         # physical path
         conversation = IConversation(self.portal.doc1)
 
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'Comment text'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Comment text"
 
         conversation.addComment(comment1)
 
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         new_id = conversation.addComment(comment)
         comment = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id),
+            f"++conversation++default/{new_id}",
         )
 
         # Add a reply to the CommentReplies adapter of the first comment
-        re_comment = createObject('plone.Comment')
-        re_comment.text = 'Comment text'
+        re_comment = createObject("plone.Comment")
+        re_comment.text = "Comment text"
         replies = IReplies(comment)
         new_re_id = replies.addComment(re_comment)
         re_comment = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_re_id),
+            f"++conversation++default/{new_re_id}",
         )
 
         # Add a reply to the reply
-        re_re_comment = createObject('plone.Comment')
-        re_re_comment.text = 'Comment text'
+        re_re_comment = createObject("plone.Comment")
+        re_re_comment.text = "Comment text"
         replies = IReplies(re_comment)
         new_re_re_id = replies.addComment(re_re_comment)
         re_re_comment = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_re_re_id),
+            f"++conversation++default/{new_re_re_id}",
         )
 
         # Add a reply to the replies reply
-        re_re_re_comment = createObject('plone.Comment')
-        re_re_re_comment.text = 'Comment text'
+        re_re_re_comment = createObject("plone.Comment")
+        re_re_re_comment.text = "Comment text"
         replies = IReplies(re_re_comment)
         new_re_re_re_id = replies.addComment(re_re_re_comment)
         re_re_re_comment = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_re_re_re_id),
+            f"++conversation++default/{new_re_re_re_id}",
         )
 
         self.assertEqual(
-            ('', 'plone', 'doc1', '++conversation++default', str(new_id)),
+            ("", "plone", "doc1", "++conversation++default", str(new_id)),
             comment.getPhysicalPath(),
         )
         self.assertEqual(
-            'http://nohost/plone/doc1/++conversation++default/' +
-            str(new_id), comment.absolute_url(),
+            "http://nohost/plone/doc1/++conversation++default/" + str(new_id),
+            comment.absolute_url(),
         )
         self.assertEqual(
-            ('', 'plone', 'doc1', '++conversation++default', str(new_re_id)),
+            ("", "plone", "doc1", "++conversation++default", str(new_re_id)),
             re_comment.getPhysicalPath(),
         )
         self.assertEqual(
-            'http://nohost/plone/doc1/++conversation++default/' +
-            str(new_re_id),
+            "http://nohost/plone/doc1/++conversation++default/" + str(new_re_id),
             re_comment.absolute_url(),
         )
         self.assertEqual(
             (
-                '', 'plone', 'doc1', '++conversation++default',
+                "",
+                "plone",
+                "doc1",
+                "++conversation++default",
                 str(new_re_re_id),
             ),
             re_re_comment.getPhysicalPath(),
         )
         self.assertEqual(
-            'http://nohost/plone/doc1/++conversation++default/' +
-            str(new_re_re_id),
+            "http://nohost/plone/doc1/++conversation++default/" + str(new_re_re_id),
             re_re_comment.absolute_url(),
         )
         self.assertEqual(
             (
-                '', 'plone', 'doc1', '++conversation++default',
+                "",
+                "plone",
+                "doc1",
+                "++conversation++default",
                 str(new_re_re_re_id),
             ),
             re_re_re_comment.getPhysicalPath(),
         )
         self.assertEqual(
-            'http://nohost/plone/doc1/++conversation++default/' +
-            str(new_re_re_re_id),
+            "http://nohost/plone/doc1/++conversation++default/" + str(new_re_re_re_id),
             re_re_re_comment.absolute_url(),
         )
diff --git a/plone/app/discussion/tests/test_comments_viewlet.py b/plone/app/discussion/tests/test_comments_viewlet.py
index 06b3231..54a18bd 100644
--- a/plone/app/discussion/tests/test_comments_viewlet.py
+++ b/plone/app/discussion/tests/test_comments_viewlet.py
@@ -1,14 +1,13 @@
-# -*- coding: utf-8 -*-
+from .. import interfaces
+from ..browser.comment import EditCommentForm
+from ..browser.comments import CommentForm
+from ..browser.comments import CommentsViewlet
+from ..interfaces import IConversation
+from ..interfaces import IDiscussionSettings
+from ..testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 from AccessControl import Unauthorized
 from datetime import datetime
 from OFS.Image import Image
-from plone.app.discussion import interfaces
-from plone.app.discussion.browser.comment import EditCommentForm
-from plone.app.discussion.browser.comments import CommentForm
-from plone.app.discussion.browser.comments import CommentsViewlet
-from plone.app.discussion.interfaces import IConversation
-from plone.app.discussion.interfaces import IDiscussionSettings
-from plone.app.discussion.testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING  # noqa
 from plone.app.testing import login
 from plone.app.testing import logout
 from plone.app.testing import setRoles
@@ -16,7 +15,6 @@ from plone.app.testing import TEST_USER_ID
 from plone.app.testing import TEST_USER_NAME
 from plone.registry.interfaces import IRegistry
 from Products.CMFCore.utils import getToolByName
-from Products.CMFPlone.tests import dummy
 from z3c.form.interfaces import IFormLayer
 from zope import interface
 from zope.annotation.interfaces import IAttributeAnnotatable
@@ -28,33 +26,67 @@ from zope.interface import alsoProvides
 from zope.interface import Interface
 from zope.publisher.browser import TestRequest
 from zope.publisher.interfaces.browser import IBrowserRequest
+from ZPublisher.HTTPRequest import FileUpload
 
+import io
 import time
 import unittest
 
 
+TEXT = b"file data"
+
+
+class DummyFile(FileUpload):
+    """Dummy upload object
+    Used to fake uploaded files.
+    """
+
+    __allow_access_to_unprotected_subobjects__ = 1
+    filename = "dummy.txt"
+    data = TEXT
+    headers = {}
+
+    def __init__(self, filename=None, data=None, headers=None):
+        if filename is not None:
+            self.filename = filename
+        if data is not None:
+            self.data = data
+        if headers is not None:
+            self.headers = headers
+        self.file = io.BytesIO(self.data)
+
+    def seek(self, *args):
+        pass
+
+    def tell(self, *args):
+        return 1
+
+    def read(self, *args):
+        return self.data
+
+
 class TestCommentForm(unittest.TestCase):
 
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        self.request = self.layer['request']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
-        self.portal.invokeFactory('Folder', 'test-folder')
-        self.folder = self.portal['test-folder']
+        self.portal = self.layer["portal"]
+        self.request = self.layer["request"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
+        self.portal.invokeFactory("Folder", "test-folder")
+        self.folder = self.portal["test-folder"]
 
         interface.alsoProvides(
             self.portal.REQUEST,
             interfaces.IDiscussionLayer,
         )
 
-        wftool = getToolByName(self.portal, 'portal_workflow')
-        wftool.doActionFor(self.portal.doc1, action='publish')
+        wftool = getToolByName(self.portal, "portal_workflow")
+        wftool.doActionFor(self.portal.doc1, action="publish")
         self.portal.doc1.allow_discussion = True
-        self.membershipTool = getToolByName(self.folder, 'portal_membership')
+        self.membershipTool = getToolByName(self.folder, "portal_membership")
         self.memberdata = self.portal.portal_memberdata
-        self.context = getattr(self.portal, 'doc1')
+        self.context = getattr(self.portal, "doc1")
 
         # Allow discussion
         registry = queryUtility(IRegistry)
@@ -62,8 +94,7 @@ class TestCommentForm(unittest.TestCase):
         settings.globally_enabled = True
 
     def test_add_comment(self):
-        """Post a comment as logged-in user.
-        """
+        """Post a comment as logged-in user."""
 
         # Allow discussion
         self.portal.doc1.allow_discussion = True
@@ -80,7 +111,7 @@ class TestCommentForm(unittest.TestCase):
             adapts=(Interface, IBrowserRequest),
             provides=Interface,
             factory=CommentForm,
-            name=u'comment-form',
+            name="comment-form",
         )
 
         # The form should return an error if the comment text field is empty
@@ -88,46 +119,45 @@ class TestCommentForm(unittest.TestCase):
 
         commentForm = getMultiAdapter(
             (self.context, request),
-            name=u'comment-form',
+            name="comment-form",
         )
         commentForm.update()
         data, errors = commentForm.extractData()  # pylint: disable-msg=W0612
 
         self.assertEqual(len(errors), 1)
-        self.assertFalse(commentForm.handleComment(commentForm, 'foo'))
+        self.assertFalse(commentForm.handleComment(commentForm, "foo"))
 
         # The form is submitted successfully, if the required text field is
         # filled out
-        request = make_request(form={'form.widgets.text': u'bar'})
+        request = make_request(form={"form.widgets.text": "bar"})
 
         commentForm = getMultiAdapter(
             (self.context, request),
-            name=u'comment-form',
+            name="comment-form",
         )
         commentForm.update()
         data, errors = commentForm.extractData()  # pylint: disable-msg=W0612
 
         self.assertEqual(len(errors), 0)
-        self.assertFalse(commentForm.handleComment(commentForm, 'foo'))
+        self.assertFalse(commentForm.handleComment(commentForm, "foo"))
 
         comments = IConversation(commentForm.context).getComments()
         comments = [comment for comment in comments]  # consume iterator
         self.assertEqual(len(comments), 1)
 
         for comment in comments:
-            self.assertEqual(comment.text, u'bar')
-            self.assertEqual(comment.creator, 'test_user_1_')
-            self.assertEqual(comment.getOwner().getUserName(), 'test-user')
+            self.assertEqual(comment.text, "bar")
+            self.assertEqual(comment.creator, "test_user_1_")
+            self.assertEqual(comment.getOwner().getUserName(), "test-user")
             local_roles = comment.get_local_roles()
             self.assertEqual(len(local_roles), 1)
             userid, roles = local_roles[0]
-            self.assertEqual(userid, 'test_user_1_')
+            self.assertEqual(userid, "test_user_1_")
             self.assertEqual(len(roles), 1)
-            self.assertEqual(roles[0], 'Owner')
+            self.assertEqual(roles[0], "Owner")
 
     def test_edit_comment(self):
-        """Edit a comment as logged-in user.
-        """
+        """Edit a comment as logged-in user."""
 
         # Allow discussion
         self.portal.doc1.allow_discussion = True
@@ -144,65 +174,64 @@ class TestCommentForm(unittest.TestCase):
             adapts=(Interface, IBrowserRequest),
             provides=Interface,
             factory=CommentForm,
-            name=u'comment-form',
+            name="comment-form",
         )
 
         provideAdapter(
             adapts=(Interface, IBrowserRequest),
             provides=Interface,
             factory=EditCommentForm,
-            name=u'edit-comment-form',
+            name="edit-comment-form",
         )
 
         # The form is submitted successfully, if the required text field is
         # filled out
-        request = make_request(form={'form.widgets.text': u'bar'})
+        request = make_request(form={"form.widgets.text": "bar"})
 
         commentForm = getMultiAdapter(
             (self.context, request),
-            name=u'comment-form',
+            name="comment-form",
         )
         commentForm.update()
         data, errors = commentForm.extractData()  # pylint: disable-msg=W0612
 
         self.assertEqual(len(errors), 0)
-        self.assertFalse(commentForm.handleComment(commentForm, 'foo'))
+        self.assertFalse(commentForm.handleComment(commentForm, "foo"))
 
         # Edit the last comment
         conversation = IConversation(self.context)
         comment = [x for x in conversation.getComments()][-1]
-        request = make_request(form={'form.widgets.text': u'foobar'})
+        request = make_request(form={"form.widgets.text": "foobar"})
         editForm = getMultiAdapter(
             (comment, request),
-            name=u'edit-comment-form',
+            name="edit-comment-form",
         )
         editForm.update()
         data, errors = editForm.extractData()  # pylint: disable-msg=W0612
 
         self.assertEqual(len(errors), 0)
-        self.assertFalse(editForm.handleComment(editForm, 'foo'))
+        self.assertFalse(editForm.handleComment(editForm, "foo"))
         comment = [x for x in conversation.getComments()][-1]
-        self.assertEqual(comment.text, u'foobar')
+        self.assertEqual(comment.text, "foobar")
 
         comments = IConversation(commentForm.context).getComments()
         comments = [c for c in comments]  # consume iterator
         self.assertEqual(len(comments), 1)
 
         for comment in comments:
-            self.assertEqual(comment.text, u'foobar')
-            self.assertEqual(comment.creator, 'test_user_1_')
+            self.assertEqual(comment.text, "foobar")
+            self.assertEqual(comment.creator, "test_user_1_")
 
-            self.assertEqual(comment.getOwner().getUserName(), 'test-user')
+            self.assertEqual(comment.getOwner().getUserName(), "test-user")
             local_roles = comment.get_local_roles()
             self.assertEqual(len(local_roles), 1)
             userid, roles = local_roles[0]
-            self.assertEqual(userid, 'test_user_1_')
+            self.assertEqual(userid, "test_user_1_")
             self.assertEqual(len(roles), 1)
-            self.assertEqual(roles[0], 'Owner')
+            self.assertEqual(roles[0], "Owner")
 
     def test_delete_comment(self):
-        """Delete a comment as logged-in user.
-        """
+        """Delete a comment as logged-in user."""
 
         # Allow discussion
         self.portal.doc1.allow_discussion = True
@@ -219,48 +248,47 @@ class TestCommentForm(unittest.TestCase):
             adapts=(Interface, IBrowserRequest),
             provides=Interface,
             factory=CommentForm,
-            name=u'comment-form',
+            name="comment-form",
         )
 
         # The form is submitted successfully, if the required text field is
         # filled out
-        form_request = make_request(form={'form.widgets.text': u'bar'})
+        form_request = make_request(form={"form.widgets.text": "bar"})
 
         commentForm = getMultiAdapter(
             (self.context, form_request),
-            name=u'comment-form',
+            name="comment-form",
         )
 
         commentForm.update()
         data, errors = commentForm.extractData()  # pylint: disable-msg=W0612
         self.assertEqual(len(errors), 0)
-        self.assertFalse(commentForm.handleComment(commentForm, 'foo'))
+        self.assertFalse(commentForm.handleComment(commentForm, "foo"))
 
         # Delete the last comment
         conversation = IConversation(self.context)
         comment = [x for x in conversation.getComments()][-1]
         deleteView = getMultiAdapter(
             (comment, self.request),
-            name=u'moderate-delete-comment',
+            name="moderate-delete-comment",
         )
         # try to delete last comment without 'Delete comments' permission
-        setRoles(self.portal, TEST_USER_ID, ['Member'])
+        setRoles(self.portal, TEST_USER_ID, ["Member"])
         self.assertRaises(
             Unauthorized,
             comment.restrictedTraverse,
-            '@@moderate-delete-comment',
+            "@@moderate-delete-comment",
         )
         deleteView()
         self.assertEqual(1, len([x for x in conversation.getComments()]))
         # try to delete last comment with 'Delete comments' permission
-        setRoles(self.portal, TEST_USER_ID, ['Reviewer'])
+        setRoles(self.portal, TEST_USER_ID, ["Reviewer"])
         deleteView()
         self.assertEqual(0, len([x for x in conversation.getComments()]))
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
 
     def test_delete_own_comment(self):
-        """Delete own comment as logged-in user.
-        """
+        """Delete own comment as logged-in user."""
 
         # Allow discussion
         self.portal.doc1.allow_discussion = True
@@ -277,42 +305,42 @@ class TestCommentForm(unittest.TestCase):
             adapts=(Interface, IBrowserRequest),
             provides=Interface,
             factory=CommentForm,
-            name=u'comment-form',
+            name="comment-form",
         )
 
         # The form is submitted successfully, if the required text field is
         # filled out
-        form_request = make_request(form={'form.widgets.text': u'bar'})
+        form_request = make_request(form={"form.widgets.text": "bar"})
 
         commentForm = getMultiAdapter(
             (self.context, form_request),
-            name=u'comment-form',
+            name="comment-form",
         )
 
         commentForm.update()
         data, errors = commentForm.extractData()  # pylint: disable-msg=W0612
         self.assertEqual(len(errors), 0)
-        self.assertFalse(commentForm.handleComment(commentForm, 'foo'))
+        self.assertFalse(commentForm.handleComment(commentForm, "foo"))
 
         # Delete the last comment
         conversation = IConversation(self.context)
         comment = [x for x in conversation.getComments()][-1]
         deleteView = getMultiAdapter(
             (comment, self.request),
-            name=u'delete-own-comment',
+            name="delete-own-comment",
         )
         # try to delete last comment with johndoe
-        setRoles(self.portal, 'johndoe', ['Member'])
-        login(self.portal, 'johndoe')
+        setRoles(self.portal, "johndoe", ["Member"])
+        login(self.portal, "johndoe")
         self.assertRaises(
             Unauthorized,
             comment.restrictedTraverse,
-            '@@delete-own-comment',
+            "@@delete-own-comment",
         )
         self.assertEqual(1, len([x for x in conversation.getComments()]))
         # try to delete last comment with the same user that created it
         login(self.portal, TEST_USER_NAME)
-        setRoles(self.portal, TEST_USER_ID, ['Member'])
+        setRoles(self.portal, TEST_USER_ID, ["Member"])
         deleteView()
         self.assertEqual(0, len([x for x in conversation.getComments()]))
 
@@ -335,40 +363,43 @@ class TestCommentForm(unittest.TestCase):
             alsoProvides(request, IAttributeAnnotatable)
             return request
 
-        provideAdapter(adapts=(Interface, IBrowserRequest),
-                       provides=Interface,
-                       factory=CommentForm,
-                       name=u'comment-form')
+        provideAdapter(
+            adapts=(Interface, IBrowserRequest),
+            provides=Interface,
+            factory=CommentForm,
+            name="comment-form",
+        )
 
         # Post an anonymous comment and provide a name
-        request = make_request(form={
-            'form.widgets.name': u'john doe',
-            'form.widgets.text': u'bar',
-        })
+        request = make_request(
+            form={
+                "form.widgets.name": "john doe",
+                "form.widgets.text": "bar",
+            }
+        )
 
         commentForm = getMultiAdapter(
             (self.context, request),
-            name=u'comment-form',
+            name="comment-form",
         )
         commentForm.update()
         data, errors = commentForm.extractData()  # pylint: disable-msg=W0612
 
         self.assertEqual(len(errors), 0)
-        self.assertFalse(commentForm.handleComment(commentForm, 'action'))
+        self.assertFalse(commentForm.handleComment(commentForm, "action"))
 
         comments = IConversation(commentForm.context).getComments()
         comments = [comment for comment in comments]  # consume itertor
         self.assertEqual(len(comments), 1)
 
         for comment in IConversation(commentForm.context).getComments():
-            self.assertEqual(comment.text, u'bar')
+            self.assertEqual(comment.text, "bar")
             self.assertIsNone(comment.creator)
             roles = comment.get_local_roles()
             self.assertEqual(len(roles), 0)
 
     def test_can_not_add_comments_if_discussion_is_not_allowed(self):
-        """Make sure that comments can't be posted if discussion is disabled.
-        """
+        """Make sure that comments can't be posted if discussion is disabled."""
 
         # Disable discussion
         registry = queryUtility(IRegistry)
@@ -382,16 +413,18 @@ class TestCommentForm(unittest.TestCase):
             alsoProvides(request, IAttributeAnnotatable)
             return request
 
-        provideAdapter(adapts=(Interface, IBrowserRequest),
-                       provides=Interface,
-                       factory=CommentForm,
-                       name=u'comment-form')
+        provideAdapter(
+            adapts=(Interface, IBrowserRequest),
+            provides=Interface,
+            factory=CommentForm,
+            name="comment-form",
+        )
 
-        request = make_request(form={'form.widgets.text': u'bar'})
+        request = make_request(form={"form.widgets.text": "bar"})
 
         commentForm = getMultiAdapter(
             (self.context, request),
-            name=u'comment-form',
+            name="comment-form",
         )
         commentForm.update()
         data, errors = commentForm.extractData()  # pylint: disable-msg=W0612
@@ -400,14 +433,11 @@ class TestCommentForm(unittest.TestCase):
         # allowed
         self.assertEqual(len(errors), 0)
 
-        self.assertRaises(Unauthorized,
-                          commentForm.handleComment,
-                          commentForm,
-                          'foo')
+        self.assertRaises(Unauthorized, commentForm.handleComment, commentForm, "foo")
 
     def test_anonymous_can_not_add_comments_if_discussion_is_not_allowed(self):
         """Make sure that anonymous users can't post comments if anonymous
-           comments are disabled.
+        comments are disabled.
         """
 
         # Anonymous comments are disabled by default
@@ -421,15 +451,16 @@ class TestCommentForm(unittest.TestCase):
             alsoProvides(request, IAttributeAnnotatable)
             return request
 
-        provideAdapter(adapts=(Interface, IBrowserRequest),
-                       provides=Interface,
-                       factory=CommentForm,
-                       name=u'comment-form')
+        provideAdapter(
+            adapts=(Interface, IBrowserRequest),
+            provides=Interface,
+            factory=CommentForm,
+            name="comment-form",
+        )
 
-        request = make_request(form={'form.widgets.text': u'bar'})
+        request = make_request(form={"form.widgets.text": "bar"})
 
-        commentForm = getMultiAdapter((self.context, request),
-                                      name=u'comment-form')
+        commentForm = getMultiAdapter((self.context, request), name="comment-form")
         commentForm.update()
         data, errors = commentForm.extractData()  # pylint: disable-msg=W0612
 
@@ -438,7 +469,7 @@ class TestCommentForm(unittest.TestCase):
             Unauthorized,
             commentForm.handleComment,
             commentForm,
-            'foo',
+            "foo",
         )
 
 
@@ -447,22 +478,22 @@ class TestCommentsViewlet(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        self.request = self.layer['request']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
-        self.portal.invokeFactory('Folder', 'test-folder')
-        self.folder = self.portal['test-folder']
+        self.portal = self.layer["portal"]
+        self.request = self.layer["request"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
+        self.portal.invokeFactory("Folder", "test-folder")
+        self.folder = self.portal["test-folder"]
         interface.alsoProvides(
             self.request,
             interfaces.IDiscussionLayer,
         )
 
-        self.workflowTool = getToolByName(self.portal, 'portal_workflow')
-        self.workflowTool.setDefaultChain('comment_one_state_workflow')
+        self.workflowTool = getToolByName(self.portal, "portal_workflow")
+        self.workflowTool.setDefaultChain("comment_one_state_workflow")
 
-        self.membershipTool = getToolByName(self.folder, 'portal_membership')
+        self.membershipTool = getToolByName(self.folder, "portal_membership")
         self.memberdata = self.portal.portal_memberdata
-        context = getattr(self.portal, 'doc1')
+        context = getattr(self.portal, "doc1")
         self.viewlet = CommentsViewlet(context, self.request, None, None)
 
         # Allow discussion
@@ -484,15 +515,14 @@ class TestCommentsViewlet(unittest.TestCase):
         # Anonymous has no 'can review' permission
         self.assertFalse(self.viewlet.can_review())
         # The reviewer role has the 'Review comments' permission
-        self.portal.acl_users._doAddUser(
-            'reviewer', 'secret', ['Reviewer'], [])
-        login(self.portal, 'reviewer')
+        self.portal.acl_users._doAddUser("reviewer", "secret", ["Reviewer"], [])
+        login(self.portal, "reviewer")
         self.assertTrue(self.viewlet.can_review())
 
     def test_can_manage(self):
         """We keep this method for backward compatibility. This method has been
-           removed in version 1.0b9 and added again in 1.0b11 because we don't
-           do API changes in beta releases.
+        removed in version 1.0b9 and added again in 1.0b11 because we don't
+        do API changes in beta releases.
         """
         # Portal owner has 'can review' permission
         self.assertTrue(self.viewlet.can_manage())
@@ -500,9 +530,8 @@ class TestCommentsViewlet(unittest.TestCase):
         # Anonymous has no 'can review' permission
         self.assertFalse(self.viewlet.can_manage())
         # The reviewer role has the 'Review comments' permission
-        self.portal.acl_users._doAddUser(
-            'reviewer', 'secret', ['Reviewer'], [])
-        login(self.portal, 'reviewer')
+        self.portal.acl_users._doAddUser("reviewer", "secret", ["Reviewer"], [])
+        login(self.portal, "reviewer")
         self.assertTrue(self.viewlet.can_manage())
 
     def test_is_discussion_allowed(self):
@@ -519,46 +548,48 @@ class TestCommentsViewlet(unittest.TestCase):
         self.assertTrue(self.viewlet.comment_transform_message())
         self.assertEqual(
             self.viewlet.comment_transform_message(),
-            'You can add a comment by filling out the form below. Plain ' +
-            'text formatting.')
+            "You can add a comment by filling out the form below. Plain "
+            + "text formatting.",
+        )
 
         # Set text transform to intelligent text
         registry = queryUtility(IRegistry)
         settings = registry.forInterface(IDiscussionSettings, check=False)
-        settings.text_transform = 'text/x-web-intelligent'
+        settings.text_transform = "text/x-web-intelligent"
 
         # Make sure the comment description changes accordingly
         self.assertEqual(
             self.viewlet.comment_transform_message(),
-            'You can add a comment by filling out the form below. ' +
-            'Plain text formatting. Web and email addresses are transformed ' +
-            'into clickable links.',
+            "You can add a comment by filling out the form below. "
+            + "Plain text formatting. Web and email addresses are transformed "
+            + "into clickable links.",
         )
 
         # Enable moderation workflow
         self.workflowTool.setChainForPortalTypes(
-            ('Discussion Item',),
-            ('comment_review_workflow,'))
+            ("Discussion Item",), ("comment_review_workflow,")
+        )
 
         # Make sure the comment description shows that comments are moderated
         self.assertEqual(
             self.viewlet.comment_transform_message(),
-            'You can add a comment by filling out the form below. ' +
-            'Plain text formatting. Web and email addresses are transformed ' +
-            'into clickable links. Comments are moderated.')
+            "You can add a comment by filling out the form below. "
+            + "Plain text formatting. Web and email addresses are transformed "
+            + "into clickable links. Comments are moderated.",
+        )
 
     def test_has_replies(self):
         self.assertEqual(self.viewlet.has_replies(), False)
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         conversation = IConversation(self.portal.doc1)
         conversation.addComment(comment)
         self.assertEqual(self.viewlet.has_replies(), True)
 
     def test_get_replies(self):
         self.assertFalse(self.viewlet.get_replies())
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         conversation = IConversation(self.portal.doc1)
         conversation.addComment(comment)
         conversation.addComment(comment)
@@ -571,7 +602,7 @@ class TestCommentsViewlet(unittest.TestCase):
             next(replies)
 
     def test_get_replies_on_non_annotatable_object(self):
-        context = self.portal.MailHost      # the mail host is not annotatable
+        context = self.portal.MailHost  # the mail host is not annotatable
         viewlet = CommentsViewlet(context, self.request, None, None)
         replies = viewlet.get_replies()
         self.assertEqual(len(tuple(replies)), 0)
@@ -581,8 +612,8 @@ class TestCommentsViewlet(unittest.TestCase):
 
     def test_get_replies_with_workflow_actions(self):
         self.assertFalse(self.viewlet.get_replies(workflow_actions=True))
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         conversation = IConversation(self.portal.doc1)
         c1 = conversation.addComment(comment)
         self.assertEqual(
@@ -591,32 +622,34 @@ class TestCommentsViewlet(unittest.TestCase):
         )
         # Enable moderation workflow
         self.workflowTool.setChainForPortalTypes(
-            ('Discussion Item',),
-            ('comment_review_workflow,'),
+            ("Discussion Item",),
+            ("comment_review_workflow,"),
         )
         # Check if workflow actions are available
         reply = next(self.viewlet.get_replies(workflow_actions=True))
-        self.assertTrue('actions' in reply)
+        self.assertTrue("actions" in reply)
         self.assertEqual(
-            reply['actions'][0]['id'],
-            'mark_as_spam',
+            reply["actions"][0]["id"],
+            "mark_as_spam",
+        )
+        expected_url = (
+            "http://nohost/plone/doc1/++conversation++default/{0}"
+            "/content_status_modify?workflow_action=mark_as_spam"
         )
-        expected_url = 'http://nohost/plone/doc1/++conversation++default/{0}' \
-                       '/content_status_modify?workflow_action=mark_as_spam'
         self.assertEqual(
-            reply['actions'][0]['url'],
+            reply["actions"][0]["url"],
             expected_url.format(int(c1)),
         )
 
     def test_get_commenter_home_url(self):
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         IConversation(self.portal.doc1)
-        portal_membership = getToolByName(self.portal, 'portal_membership')
+        portal_membership = getToolByName(self.portal, "portal_membership")
         m = portal_membership.getAuthenticatedMember()
         self.assertEqual(
             self.viewlet.get_commenter_home_url(m.getUserName()),
-            'http://nohost/plone/author/test-user',
+            "http://nohost/plone/author/test-user",
         )
 
     def test_get_commenter_home_url_is_none(self):
@@ -625,72 +658,77 @@ class TestCommentsViewlet(unittest.TestCase):
     def test_get_commenter_portrait(self):
 
         # Add a user with a member image
-        self.membershipTool.addMember('jim', 'Jim', ['Member'], [])
-        self.memberdata._setPortrait(Image(
-            id='jim',
-            file=dummy.File(),
-            title='',
-        ), 'jim')
-        self.assertEqual(
-            self.memberdata._getPortrait('jim').getId(),
-            'jim',
+        self.membershipTool.addMember("jim", "Jim", ["Member"], [])
+        self.memberdata._setPortrait(
+            Image(
+                id="jim",
+                file=DummyFile(),
+                title="",
+            ),
+            "jim",
         )
         self.assertEqual(
-            self.memberdata._getPortrait('jim').meta_type,
-            'Image',
+            self.memberdata._getPortrait("jim").getId(),
+            "jim",
+        )
+        self.assertEqual(
+            self.memberdata._getPortrait("jim").meta_type,
+            "Image",
         )
 
         # Add a conversation with a comment
         conversation = IConversation(self.portal.doc1)
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
-        comment.Creator = 'Jim'
-        comment.author_username = 'jim'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
+        comment.Creator = "Jim"
+        comment.author_username = "jim"
         conversation.addComment(comment)
 
         # Call get_commenter_portrait method of the viewlet
         self.viewlet.update()
-        portrait_url = self.viewlet.get_commenter_portrait('jim')
+        portrait_url = self.viewlet.get_commenter_portrait("jim")
 
         # Check if the correct member image URL is returned
         self.assertEqual(
             portrait_url,
-            'http://nohost/plone/portal_memberdata/portraits/jim',
+            "http://nohost/plone/portal_memberdata/portraits/jim",
         )
 
     def test_get_commenter_portrait_is_none(self):
 
         self.assertTrue(
-            self.viewlet.get_commenter_portrait() in (
-                'defaultUser.png',
-                'defaultUser.gif',
+            self.viewlet.get_commenter_portrait()
+            in (
+                "defaultUser.png",
+                "defaultUser.gif",
             ),
         )
 
     def test_get_commenter_portrait_without_userimage(self):
 
         # Create a user without a user image
-        self.membershipTool.addMember('jim', 'Jim', ['Member'], [])
+        self.membershipTool.addMember("jim", "Jim", ["Member"], [])
 
         # Add a conversation with a comment
         conversation = IConversation(self.portal.doc1)
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
-        comment.Creator = 'Jim'
-        comment.author_username = 'jim'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
+        comment.Creator = "Jim"
+        comment.author_username = "jim"
         conversation.addComment(comment)
 
         # Call get_commenter_portrait method of the viewlet
         self.viewlet.update()
-        portrait_url = self.viewlet.get_commenter_portrait('jim')
+        portrait_url = self.viewlet.get_commenter_portrait("jim")
 
         # Check if the correct default member image URL is returned.
         # Note that Products.PlonePAS 4.0.5 and later have .png and
         # earlier versions have .gif.
         self.assertTrue(
-            portrait_url in (
-                'http://nohost/plone/defaultUser.png',
-                'http://nohost/plone/defaultUser.gif',
+            portrait_url
+            in (
+                "http://nohost/plone/defaultUser.png",
+                "http://nohost/plone/defaultUser.gif",
             ),
         )
 
@@ -700,8 +738,8 @@ class TestCommentsViewlet(unittest.TestCase):
         # Allow anonymous discussion
         registry = queryUtility(IRegistry)
         registry[
-            'plone.app.discussion.interfaces.IDiscussionSettings.' +
-            'anonymous_comments'
+            "plone.app.discussion.interfaces.IDiscussionSettings."
+            + "anonymous_comments"
         ] = True
         # Test if anonymous discussion is allowed for the viewlet
         self.assertTrue(self.viewlet.anonymous_discussion_allowed())
@@ -710,8 +748,8 @@ class TestCommentsViewlet(unittest.TestCase):
         self.assertTrue(self.viewlet.show_commenter_image())
         registry = queryUtility(IRegistry)
         registry[
-            'plone.app.discussion.interfaces.IDiscussionSettings.' +
-            'show_commenter_image'
+            "plone.app.discussion.interfaces.IDiscussionSettings."
+            + "show_commenter_image"
         ] = False
         self.assertFalse(self.viewlet.show_commenter_image())
 
@@ -724,7 +762,7 @@ class TestCommentsViewlet(unittest.TestCase):
         self.viewlet.update()
         self.assertEqual(
             self.viewlet.login_action(),
-            'http://nohost/plone/login_form?came_from=http%3A//nohost',
+            "http://nohost/plone/login_form?came_from=http%3A//nohost",
         )
 
     def test_format_time(self):
@@ -737,9 +775,8 @@ class TestCommentsViewlet(unittest.TestCase):
         # a correct utc time that can be used to make datetime set the utc
         # time of the local time given above. That way, the time for the
         # example below is correct within each time zone, independent of DST
-        python_time = datetime(
-            *time.gmtime(time.mktime(python_time.timetuple()))[:7])
+        python_time = datetime(*time.gmtime(time.mktime(python_time.timetuple()))[:7])
         localized_time = self.viewlet.format_time(python_time)
         self.assertTrue(
-            localized_time in ['Feb 01, 2009 11:32 PM', '2009-02-01 23:32'],
+            localized_time in ["Feb 01, 2009 11:32 PM", "2009-02-01 23:32"],
         )
diff --git a/plone/app/discussion/tests/test_contentrules.py b/plone/app/discussion/tests/test_contentrules.py
index c05aede..506a538 100644
--- a/plone/app/discussion/tests/test_contentrules.py
+++ b/plone/app/discussion/tests/test_contentrules.py
@@ -1,11 +1,12 @@
-# -*- coding: utf-8 -*-
 from plone.app.discussion.interfaces import ICommentAddedEvent
 from plone.app.discussion.interfaces import ICommentRemovedEvent
 from plone.app.discussion.interfaces import IConversation
 from plone.app.discussion.interfaces import IReplies
 from plone.app.discussion.interfaces import IReplyAddedEvent
 from plone.app.discussion.interfaces import IReplyRemovedEvent
-from plone.app.discussion.testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING  # noqa
+from plone.app.discussion.testing import (  # noqa
+    PLONE_APP_DISCUSSION_INTEGRATION_TESTING,
+)
 from plone.app.testing import setRoles
 from plone.app.testing import TEST_USER_ID
 from plone.contentrules.rule.interfaces import IRuleEventType
@@ -17,31 +18,33 @@ import unittest
 
 
 class CommentContentRulesTest(unittest.TestCase):
-    """ Test custom comments events
-    """
+    """Test custom comments events"""
+
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
         # Setup sandbox
-        self.portal = self.layer['portal']
-        self.request = self.layer['request']
+        self.portal = self.layer["portal"]
+        self.request = self.layer["request"]
 
         # Setup current user properties
         member = self.portal.portal_membership.getMemberById(TEST_USER_ID)
-        member.setMemberProperties({
-            'fullname': 'X Manager',
-            'email': 'xmanager@example.com',
-        })
+        member.setMemberProperties(
+            {
+                "fullname": "X Manager",
+                "email": "xmanager@example.com",
+            }
+        )
 
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
 
-        self.document = self.portal['doc1']
+        self.document = self.portal["doc1"]
 
-        comment = createObject('plone.Comment')
-        comment.text = 'This is a comment'
-        comment.author_username = 'jim'
-        comment.author_name = 'Jim'
-        comment.author_email = 'jim@example.com'
+        comment = createObject("plone.Comment")
+        comment.text = "This is a comment"
+        comment.author_username = "jim"
+        comment.author_name = "Jim"
+        comment.author_email = "jim@example.com"
         conversation = IConversation(self.document)
         conversation.addComment(comment)
 
@@ -52,58 +55,61 @@ class CommentContentRulesTest(unittest.TestCase):
         self.assertTrue(IRuleEventType.providedBy(IReplyRemovedEvent))
 
     def testCommentIdStringSubstitution(self):
-        comment_id = getAdapter(self.document, IStringSubstitution,
-                                name=u'comment_id')
+        comment_id = getAdapter(self.document, IStringSubstitution, name="comment_id")
         self.assertIsInstance(comment_id(), int)
 
     def testCommentTextStringSubstitution(self):
-        comment_text = getAdapter(self.document, IStringSubstitution,
-                                  name=u'comment_text')
-        self.assertEqual(comment_text(), u'This is a comment')
+        comment_text = getAdapter(
+            self.document, IStringSubstitution, name="comment_text"
+        )
+        self.assertEqual(comment_text(), "This is a comment")
 
     def testCommentUserIdStringSubstitution(self):
-        comment_user_id = getAdapter(self.document, IStringSubstitution,
-                                     name=u'comment_user_id')
-        self.assertEqual(comment_user_id(), u'jim')
+        comment_user_id = getAdapter(
+            self.document, IStringSubstitution, name="comment_user_id"
+        )
+        self.assertEqual(comment_user_id(), "jim")
 
     def testCommentUserFullNameStringSubstitution(self):
-        comment_user_fullname = getAdapter(self.document, IStringSubstitution,
-                                           name=u'comment_user_fullname')
-        self.assertEqual(comment_user_fullname(), u'Jim')
+        comment_user_fullname = getAdapter(
+            self.document, IStringSubstitution, name="comment_user_fullname"
+        )
+        self.assertEqual(comment_user_fullname(), "Jim")
 
     def testCommentUserEmailStringSubstitution(self):
-        comment_user_email = getAdapter(self.document, IStringSubstitution,
-                                        name=u'comment_user_email')
-        self.assertEqual(comment_user_email(), u'jim@example.com')
+        comment_user_email = getAdapter(
+            self.document, IStringSubstitution, name="comment_user_email"
+        )
+        self.assertEqual(comment_user_email(), "jim@example.com")
 
 
 class ReplyContentRulesTest(unittest.TestCase):
-    """ Test custom comments events
-    """
+    """Test custom comments events"""
+
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
         # Setup sandbox
-        self.portal = self.layer['portal']
-        self.request = self.layer['request']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        self.portal = self.layer["portal"]
+        self.request = self.layer["request"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
 
-        self.document = self.portal['doc1']
+        self.document = self.portal["doc1"]
         conversation = IConversation(self.document)
         replies = IReplies(conversation)
 
-        comment = createObject('plone.Comment')
-        comment.text = 'This is a comment'
+        comment = createObject("plone.Comment")
+        comment.text = "This is a comment"
         new_id = replies.addComment(comment)
         comment = self.document.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id),
+            f"++conversation++default/{new_id}",
         )
 
-        re_comment = createObject('plone.Comment')
-        re_comment.text = 'This is a reply'
-        re_comment.author_username = 'julia'
-        re_comment.author_name = 'Juliana'
-        re_comment.author_email = 'julia@example.com'
+        re_comment = createObject("plone.Comment")
+        re_comment.text = "This is a reply"
+        re_comment.author_username = "julia"
+        re_comment.author_name = "Juliana"
+        re_comment.author_email = "julia@example.com"
 
         replies = IReplies(comment)
         replies.addComment(re_comment)
@@ -112,7 +118,7 @@ class ReplyContentRulesTest(unittest.TestCase):
         reply_id = getAdapter(
             self.document,
             IStringSubstitution,
-            name=u'comment_id',
+            name="comment_id",
         )
         self.assertIsInstance(reply_id(), int)
 
@@ -120,30 +126,30 @@ class ReplyContentRulesTest(unittest.TestCase):
         reply_text = getAdapter(
             self.document,
             IStringSubstitution,
-            name=u'comment_text',
+            name="comment_text",
         )
-        self.assertEqual(reply_text(), u'This is a reply')
+        self.assertEqual(reply_text(), "This is a reply")
 
     def testReplyUserIdStringSubstitution(self):
         reply_user_id = getAdapter(
             self.document,
             IStringSubstitution,
-            name=u'comment_user_id',
+            name="comment_user_id",
         )
-        self.assertEqual(reply_user_id(), u'julia')
+        self.assertEqual(reply_user_id(), "julia")
 
     def testReplyUserFullNameStringSubstitution(self):
         reply_user_fullname = getAdapter(
             self.document,
             IStringSubstitution,
-            name=u'comment_user_fullname',
+            name="comment_user_fullname",
         )
-        self.assertEqual(reply_user_fullname(), u'Juliana')
+        self.assertEqual(reply_user_fullname(), "Juliana")
 
     def testReplyUserEmailStringSubstitution(self):
         reply_user_email = getAdapter(
             self.document,
             IStringSubstitution,
-            name=u'comment_user_email',
+            name="comment_user_email",
         )
-        self.assertEqual(reply_user_email(), u'julia@example.com')
+        self.assertEqual(reply_user_email(), "julia@example.com")
diff --git a/plone/app/discussion/tests/test_controlpanel.py b/plone/app/discussion/tests/test_controlpanel.py
index 4ad3018..b148547 100644
--- a/plone/app/discussion/tests/test_controlpanel.py
+++ b/plone/app/discussion/tests/test_controlpanel.py
@@ -1,6 +1,7 @@
-# -*- coding: utf-8 -*-
 from plone.app.discussion.interfaces import IDiscussionSettings
-from plone.app.discussion.testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING  # noqa
+from plone.app.discussion.testing import (  # noqa
+    PLONE_APP_DISCUSSION_INTEGRATION_TESTING,
+)
 from plone.app.testing import setRoles
 from plone.app.testing import TEST_USER_ID
 from plone.registry import Registry
@@ -17,8 +18,8 @@ class RegistryTest(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
         self.registry = Registry()
         self.registry.registerInterface(IDiscussionSettings)
 
@@ -29,99 +30,100 @@ class RegistryTest(unittest.TestCase):
     def test_discussion_controlpanel_view(self):
         view = getMultiAdapter(
             (self.portal, self.portal.REQUEST),
-            name='discussion-controlpanel',
+            name="discussion-controlpanel",
         )
         self.assertTrue(view())
 
     def test_discussion_in_controlpanel(self):
         # Check if discussion is in the control panel
-        self.controlpanel = getToolByName(self.portal, 'portal_controlpanel')
+        self.controlpanel = getToolByName(self.portal, "portal_controlpanel")
         self.assertTrue(
-            'discussion' in [
-                a.getAction(self)['id']
-                for a in self.controlpanel.listActions()
-            ],
+            "discussion"
+            in [a.getAction(self)["id"] for a in self.controlpanel.listActions()],
         )
 
     def test_globally_enabled(self):
         # Check globally_enabled record
-        self.assertTrue('globally_enabled' in IDiscussionSettings)
+        self.assertTrue("globally_enabled" in IDiscussionSettings)
         self.assertEqual(
             self.registry[
-                'plone.app.discussion.interfaces.' +
-                'IDiscussionSettings.globally_enabled'
+                "plone.app.discussion.interfaces."
+                + "IDiscussionSettings.globally_enabled"
             ],
             False,
         )
 
     def test_anonymous_comments(self):
         # Check anonymous_comments record
-        self.assertTrue('anonymous_comments' in IDiscussionSettings)
+        self.assertTrue("anonymous_comments" in IDiscussionSettings)
         self.assertEqual(
             self.registry[
-                'plone.app.discussion.interfaces.' +
-                'IDiscussionSettings.anonymous_comments'
+                "plone.app.discussion.interfaces."
+                + "IDiscussionSettings.anonymous_comments"
             ],
             False,
         )
 
     def test_moderation_enabled(self):
         # Check globally_enabled record
-        self.assertTrue('moderation_enabled' in IDiscussionSettings)
+        self.assertTrue("moderation_enabled" in IDiscussionSettings)
         self.assertEqual(
             self.registry[
-                'plone.app.discussion.interfaces.' +
-                'IDiscussionSettings.moderation_enabled'
+                "plone.app.discussion.interfaces."
+                + "IDiscussionSettings.moderation_enabled"
             ],
             False,
         )
 
     def test_edit_comment_enabled(self):
         # Check edit_comment_enabled record
-        self.assertTrue('edit_comment_enabled' in IDiscussionSettings)
+        self.assertTrue("edit_comment_enabled" in IDiscussionSettings)
         self.assertEqual(
-            self.registry['plone.app.discussion.interfaces.' +
-                          'IDiscussionSettings.edit_comment_enabled'],
+            self.registry[
+                "plone.app.discussion.interfaces."
+                + "IDiscussionSettings.edit_comment_enabled"
+            ],
             False,
         )
 
     def test_delete_own_comment_enabled(self):
         # Check delete_own_comment_enabled record
-        self.assertTrue('delete_own_comment_enabled' in IDiscussionSettings)
+        self.assertTrue("delete_own_comment_enabled" in IDiscussionSettings)
         self.assertEqual(
-            self.registry['plone.app.discussion.interfaces.' +
-                          'IDiscussionSettings.delete_own_comment_enabled'],
+            self.registry[
+                "plone.app.discussion.interfaces."
+                + "IDiscussionSettings.delete_own_comment_enabled"
+            ],
             False,
         )
 
     def test_text_transform(self):
-        self.assertTrue('text_transform' in IDiscussionSettings)
+        self.assertTrue("text_transform" in IDiscussionSettings)
         self.assertEqual(
             self.registry[
-                'plone.app.discussion.interfaces.' +
-                'IDiscussionSettings.text_transform'
+                "plone.app.discussion.interfaces."
+                + "IDiscussionSettings.text_transform"
             ],
-            'text/plain',
+            "text/plain",
         )
 
     def test_captcha(self):
         # Check globally_enabled record
-        self.assertTrue('captcha' in IDiscussionSettings)
+        self.assertTrue("captcha" in IDiscussionSettings)
         self.assertEqual(
             self.registry[
-                'plone.app.discussion.interfaces.' +
-                'IDiscussionSettings.captcha'
+                "plone.app.discussion.interfaces." + "IDiscussionSettings.captcha"
             ],
-            'disabled',
+            "disabled",
         )
 
     def test_show_commenter_image(self):
         # Check show_commenter_image record
-        self.assertTrue('show_commenter_image' in IDiscussionSettings)
+        self.assertTrue("show_commenter_image" in IDiscussionSettings)
         self.assertEqual(
             self.registry[
-                'plone.app.discussion.interfaces.' +
-                'IDiscussionSettings.show_commenter_image'
+                "plone.app.discussion.interfaces."
+                + "IDiscussionSettings.show_commenter_image"
             ],
             True,
         )
@@ -129,12 +131,12 @@ class RegistryTest(unittest.TestCase):
     def test_moderator_notification_enabled(self):
         # Check show_commenter_image record
         self.assertTrue(
-            'moderator_notification_enabled' in IDiscussionSettings,
+            "moderator_notification_enabled" in IDiscussionSettings,
         )
         self.assertEqual(
             self.registry[
-                'plone.app.discussion.interfaces.' +
-                'IDiscussionSettings.moderator_notification_enabled'
+                "plone.app.discussion.interfaces."
+                + "IDiscussionSettings.moderator_notification_enabled"
             ],
             False,
         )
@@ -154,22 +156,22 @@ class ConfigurationChangedSubscriberTest(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
         registry = queryUtility(IRegistry)
         self.settings = registry.forInterface(IDiscussionSettings, check=False)
 
     def test_moderation_enabled_in_discussion_control_panel_changed(self):
         """Make sure the 'Discussion Item' workflow is changed properly, when
-           the 'comment_moderation' setting in the discussion control panel
-           changes.
+        the 'comment_moderation' setting in the discussion control panel
+        changes.
         """
         # By default the comment_one_state_workflow without moderation is
         # enabled
         self.assertEqual(
-            ('comment_one_state_workflow',),
+            ("comment_one_state_workflow",),
             self.portal.portal_workflow.getChainForPortalType(
-                'Discussion Item',
+                "Discussion Item",
             ),
         )
 
@@ -179,32 +181,32 @@ class ConfigurationChangedSubscriberTest(unittest.TestCase):
         # Make sure the comment_review_workflow with moderation enabled is
         # enabled
         self.assertEqual(
-            ('comment_review_workflow',),
+            ("comment_review_workflow",),
             self.portal.portal_workflow.getChainForPortalType(
-                'Discussion Item',
+                "Discussion Item",
             ),
         )
         # And back
         self.settings.moderation_enabled = False
         self.assertEqual(
-            ('comment_one_state_workflow',),
+            ("comment_one_state_workflow",),
             self.portal.portal_workflow.getChainForPortalType(
-                'Discussion Item',
+                "Discussion Item",
             ),
         )
 
     def test_change_workflow_in_types_control_panel(self):
         """Make sure the setting in the discussion control panel is changed
-           accordingly, when the workflow for the 'Discussion Item' changed in
-           the types control panel.
+        accordingly, when the workflow for the 'Discussion Item' changed in
+        the types control panel.
         """
         # By default, moderation is disabled
         self.settings.moderation_enabled = False
 
         # Enable the 'comment_review_workflow' with moderation enabled
         self.portal.portal_workflow.setChainForPortalTypes(
-            ('Discussion Item',),
-            ('comment_review_workflow',),
+            ("Discussion Item",),
+            ("comment_review_workflow",),
         )
 
         # Make sure the moderation_enabled settings has changed
@@ -212,15 +214,15 @@ class ConfigurationChangedSubscriberTest(unittest.TestCase):
 
         # Enable the 'comment_review_workflow' with moderation enabled
         self.portal.portal_workflow.setChainForPortalTypes(
-            ('Discussion Item',),
-            ('comment_one_state_workflow',),
+            ("Discussion Item",),
+            ("comment_one_state_workflow",),
         )
         self.settings.moderation_enabled = True
 
         # Enable a 'custom' discussion workflow
         self.portal.portal_workflow.setChainForPortalTypes(
-            ('Discussion Item',),
-            ('intranet_workflow',),
+            ("Discussion Item",),
+            ("intranet_workflow",),
         )
 
         # Setting has not changed. A Custom workflow disables the
diff --git a/plone/app/discussion/tests/test_conversation.py b/plone/app/discussion/tests/test_conversation.py
index fcf528c..febce28 100644
--- a/plone/app/discussion/tests/test_conversation.py
+++ b/plone/app/discussion/tests/test_conversation.py
@@ -1,17 +1,17 @@
-# -*- coding: utf-8 -*-
+from ..interfaces import IComment
+from ..interfaces import IConversation
+from ..interfaces import IDiscussionLayer
+from ..interfaces import IDiscussionSettings
+from ..interfaces import IReplies
+from ..testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 from Acquisition import aq_base
 from Acquisition import aq_parent
 from datetime import datetime
 from datetime import timedelta
-from plone.app.discussion import interfaces
-from plone.app.discussion.interfaces import IComment
-from plone.app.discussion.interfaces import IConversation
-from plone.app.discussion.interfaces import IDiscussionSettings
-from plone.app.discussion.interfaces import IReplies
-from plone.app.discussion.testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING  # noqa
 from plone.app.testing import setRoles
 from plone.app.testing import TEST_USER_ID
 from plone.app.vocabularies.types import BAD_TYPES
+from plone.dexterity.interfaces import IDexterityContent
 from plone.registry.interfaces import IRegistry
 from Products.CMFCore.utils import getToolByName
 from zope import interface
@@ -19,31 +19,22 @@ from zope.annotation.interfaces import IAnnotations
 from zope.component import createObject
 from zope.component import queryUtility
 
-import six
 import unittest
 
 
-try:
-    from plone.dexterity.interfaces import IDexterityContent
-    DEXTERITY = True
-except ImportError:
-    DEXTERITY = False
-
-
 class ConversationTest(unittest.TestCase):
 
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
-        interface.alsoProvides(
-            self.portal.REQUEST, interfaces.IDiscussionLayer)
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
+        interface.alsoProvides(self.portal.REQUEST, IDiscussionLayer)
 
         self.typetool = self.portal.portal_types
         self.portal_discussion = getToolByName(
             self.portal,
-            'portal_discussion',
+            "portal_discussion",
             None,
         )
         # Allow discussion
@@ -52,7 +43,7 @@ class ConversationTest(unittest.TestCase):
         settings.globally_enabled = True
 
         workflow = self.portal.portal_workflow
-        workflow.doActionFor(self.portal.doc1, 'publish')
+        workflow.doActionFor(self.portal.doc1, "publish")
 
     def test_add_comment(self):
         # Create a conversation. In this case we doesn't assign it to an
@@ -62,8 +53,8 @@ class ConversationTest(unittest.TestCase):
         # Add a comment. Note: in real life, we always create comments via the
         # factory to allow different factories to be swapped in
 
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
 
         new_id = conversation.addComment(comment)
 
@@ -79,20 +70,19 @@ class ConversationTest(unittest.TestCase):
         self.assertEqual(len(tuple(conversation.getThreads())), 1)
         self.assertEqual(conversation.total_comments(), 1)
         self.assertTrue(
-            conversation.last_comment_date - datetime.utcnow() <
-            timedelta(seconds=1),
+            conversation.last_comment_date - datetime.utcnow() < timedelta(seconds=1),
         )
 
     def test_private_comment(self):
         conversation = IConversation(self.portal.doc1)
 
-        comment = createObject('plone.Comment')
-        comment.author_username = 'nobody'
+        comment = createObject("plone.Comment")
+        comment.author_username = "nobody"
         conversation.addComment(comment)
-        comment.manage_permission('View', roles=tuple())
+        comment.manage_permission("View", roles=tuple())
         self.assertEqual(0, conversation.total_comments())
         self.assertEqual(None, conversation.last_comment_date)
-        self.assertEqual(['nobody'], list(conversation.commentators))
+        self.assertEqual(["nobody"], list(conversation.commentators))
         self.assertEqual([], list(conversation.public_commentators))
 
     def test_delete_comment(self):
@@ -103,8 +93,8 @@ class ConversationTest(unittest.TestCase):
         # Add a comment. Note: in real life, we always create comments via the
         # factory to allow different factories to be swapped in
 
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
 
         new_id = conversation.addComment(comment)
 
@@ -139,23 +129,23 @@ class ConversationTest(unittest.TestCase):
         #    +- Comment 2_1
 
         # Create all comments
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'Comment text'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Comment text"
 
-        comment1_1 = createObject('plone.Comment')
-        comment1_1.text = 'Comment text'
+        comment1_1 = createObject("plone.Comment")
+        comment1_1.text = "Comment text"
 
-        comment1_1_1 = createObject('plone.Comment')
-        comment1_1_1.text = 'Comment text'
+        comment1_1_1 = createObject("plone.Comment")
+        comment1_1_1.text = "Comment text"
 
-        comment1_2 = createObject('plone.Comment')
-        comment1_2.text = 'Comment text'
+        comment1_2 = createObject("plone.Comment")
+        comment1_2.text = "Comment text"
 
-        comment2 = createObject('plone.Comment')
-        comment2.text = 'Comment text'
+        comment2 = createObject("plone.Comment")
+        comment2.text = "Comment text"
 
-        comment2_1 = createObject('plone.Comment')
-        comment2_1.text = 'Comment text'
+        comment2_1 = createObject("plone.Comment")
+        comment2_1.text = "Comment text"
 
         # Create the nested comment structure
         new_id_1 = conversation.addComment(comment1)
@@ -175,21 +165,24 @@ class ConversationTest(unittest.TestCase):
 
         del conversation[new_id_1]
 
-        self.assertEqual([
-            {'comment': comment2, 'depth': 0, 'id': new_id_2},
-            {'comment': comment2_1, 'depth': 1, 'id': new_id_2_1},
-        ], list(conversation.getThreads()))
+        self.assertEqual(
+            [
+                {"comment": comment2, "depth": 0, "id": new_id_2},
+                {"comment": comment2_1, "depth": 1, "id": new_id_2_1},
+            ],
+            list(conversation.getThreads()),
+        )
 
     def test_delete_comment_when_content_object_is_deleted(self):
         # Make sure all comments of a content object are deleted when the
         # object itself is deleted.
         conversation = IConversation(self.portal.doc1)
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         conversation.addComment(comment)
 
         # Delete the content object
-        self.portal.manage_delObjects(['doc1'])
+        self.portal.manage_delObjects(["doc1"])
 
         # Make sure the comment has been deleted as well
         self.assertEqual(len(list(conversation.getComments())), 0)
@@ -198,8 +191,8 @@ class ConversationTest(unittest.TestCase):
 
     def test_comments_enabled_on_doc_in_subfolder(self):
         typetool = self.portal.portal_types
-        typetool.constructContent('Folder', self.portal, 'folder1')
-        typetool.constructContent('Document', self.portal.folder1, 'doc2')
+        typetool.constructContent("Folder", self.portal, "folder1")
+        typetool.constructContent("Document", self.portal.folder1, "doc2")
 
         folder = self.portal.folder1
 
@@ -209,13 +202,13 @@ class ConversationTest(unittest.TestCase):
         self.assertFalse(aq_base(folder).allow_discussion)
 
         doc = self.portal.folder1.doc2
-        conversation = doc.restrictedTraverse('@@conversation_view')
+        conversation = doc.restrictedTraverse("@@conversation_view")
         self.assertEqual(conversation.enabled(), False)
 
         # We have to allow discussion on Document content type, since
         # otherwise allow_discussion will always return False
-        portal_types = getToolByName(self.portal, 'portal_types')
-        document_fti = getattr(portal_types, 'Document')
+        portal_types = getToolByName(self.portal, "portal_types")
+        document_fti = getattr(portal_types, "Document")
         document_fti.manage_changeProperties(allow_discussion=True)
 
         self.assertEqual(conversation.enabled(), True)
@@ -223,13 +216,12 @@ class ConversationTest(unittest.TestCase):
     def test_disable_commenting_globally(self):
 
         # Create a conversation.
-        conversation = self.portal.doc1.restrictedTraverse(
-            '@@conversation_view')
+        conversation = self.portal.doc1.restrictedTraverse("@@conversation_view")
 
         # We have to allow discussion on Document content type, since
         # otherwise allow_discussion will always return False
-        portal_types = getToolByName(self.portal, 'portal_types')
-        document_fti = getattr(portal_types, 'Document')
+        portal_types = getToolByName(self.portal, "portal_types")
+        document_fti = getattr(portal_types, "Document")
         document_fti.manage_changeProperties(allow_discussion=True)
 
         # Check if conversation is enabled now
@@ -249,14 +241,14 @@ class ConversationTest(unittest.TestCase):
 
     def test_allow_discussion_for_news_items(self):
 
-        self.typetool.constructContent('News Item', self.portal, 'newsitem')
+        self.typetool.constructContent("News Item", self.portal, "newsitem")
         newsitem = self.portal.newsitem
-        conversation = newsitem.restrictedTraverse('@@conversation_view')
+        conversation = newsitem.restrictedTraverse("@@conversation_view")
 
         # We have to allow discussion on Document content type, since
         # otherwise allow_discussion will always return False
-        portal_types = getToolByName(self.portal, 'portal_types')
-        document_fti = getattr(portal_types, 'News Item')
+        portal_types = getToolByName(self.portal, "portal_types")
+        document_fti = getattr(portal_types, "News Item")
         document_fti.manage_changeProperties(allow_discussion=True)
 
         # Check if conversation is enabled now
@@ -278,23 +270,23 @@ class ConversationTest(unittest.TestCase):
 
         # Create a conversation.
         conversation = self.portal.doc1.restrictedTraverse(
-            '@@conversation_view',
+            "@@conversation_view",
         )
 
         # The Document content type is disabled by default
         self.assertEqual(conversation.enabled(), False)
 
         # Allow discussion on Document content type
-        portal_types = getToolByName(self.portal, 'portal_types')
-        document_fti = getattr(portal_types, 'Document')
+        portal_types = getToolByName(self.portal, "portal_types")
+        document_fti = getattr(portal_types, "Document")
         document_fti.manage_changeProperties(allow_discussion=True)
 
         # Check if conversation is enabled now
         self.assertEqual(conversation.enabled(), True)
 
         # Disallow discussion on Document content type
-        portal_types = getToolByName(self.portal, 'portal_types')
-        document_fti = getattr(portal_types, 'Document')
+        portal_types = getToolByName(self.portal, "portal_types")
+        document_fti = getattr(portal_types, "Document")
         document_fti.manage_changeProperties(allow_discussion=False)
 
         # Check if conversation is enabled now
@@ -306,17 +298,17 @@ class ConversationTest(unittest.TestCase):
         # plone.app.contenttypes does not have this restriction any longer.
 
         # Create a folder
-        self.typetool.constructContent('Folder', self.portal, 'f1')
+        self.typetool.constructContent("Folder", self.portal, "f1")
 
         # Usually we don't create a conversation on a folder
-        conversation = self.portal.f1.restrictedTraverse('@@conversation_view')
+        conversation = self.portal.f1.restrictedTraverse("@@conversation_view")
 
         # Allow discussion for the folder
         self.portal.f1.allow_discussion = True
 
         # Allow discussion on Folder content type
-        portal_types = getToolByName(self.portal, 'portal_types')
-        document_fti = getattr(portal_types, 'Folder')
+        portal_types = getToolByName(self.portal, "portal_types")
+        document_fti = getattr(portal_types, "Folder")
         document_fti.manage_changeProperties(allow_discussion=True)
 
         self.assertTrue(conversation.enabled())
@@ -326,7 +318,7 @@ class ConversationTest(unittest.TestCase):
 
         # Create a conversation.
         conversation = self.portal.doc1.restrictedTraverse(
-            '@@conversation_view',
+            "@@conversation_view",
         )
 
         # Discussion is disallowed by default
@@ -351,13 +343,13 @@ class ConversationTest(unittest.TestCase):
         # Add a comment. Note: in real life, we always create comments via the
         # factory to allow different factories to be swapped in
 
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'Comment text'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Comment text"
 
         new_id1 = conversation.addComment(comment1)
 
-        comment2 = createObject('plone.Comment')
-        comment2.text = 'Comment text'
+        comment2 = createObject("plone.Comment")
+        comment2.text = "Comment text"
 
         new_id2 = conversation.addComment(comment2)
 
@@ -384,17 +376,17 @@ class ConversationTest(unittest.TestCase):
         self.assertTrue(comment2 in conversation.values())
 
         # check if comment ids are in iterkeys
-        self.assertTrue(new_id1 in six.iterkeys(conversation))
-        self.assertTrue(new_id2 in six.iterkeys(conversation))
-        self.assertFalse(123 in six.iterkeys(conversation))
+        self.assertTrue(new_id1 in conversation.keys())
+        self.assertTrue(new_id2 in conversation.keys())
+        self.assertFalse(123 in conversation.keys())
 
         # check if comment objects are in itervalues
-        self.assertTrue(comment1 in six.itervalues(conversation))
-        self.assertTrue(comment2 in six.itervalues(conversation))
+        self.assertTrue(comment1 in conversation.values())
+        self.assertTrue(comment2 in conversation.values())
 
         # check if iteritems returns (key, comment object) pairs
-        self.assertTrue((new_id1, comment1) in six.iteritems(conversation))
-        self.assertTrue((new_id2, comment2) in six.iteritems(conversation))
+        self.assertTrue((new_id1, comment1) in conversation.items())
+        self.assertTrue((new_id2, comment2) in conversation.items())
 
         # TODO test acquisition wrapping  # noqa T000
         # self.assertTrue(aq_base(aq_parent(comment1)) is conversation)
@@ -408,14 +400,14 @@ class ConversationTest(unittest.TestCase):
         # comments via the factory to allow different factories to be
         # swapped in
 
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'Comment text'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Comment text"
 
-        comment2 = createObject('plone.Comment')
-        comment2.text = 'Comment text'
+        comment2 = createObject("plone.Comment")
+        comment2.text = "Comment text"
 
-        comment3 = createObject('plone.Comment')
-        comment3.text = 'Comment text'
+        comment3 = createObject("plone.Comment")
+        comment3.text = "Comment text"
 
         conversation.addComment(comment1)
         conversation.addComment(comment2)
@@ -437,49 +429,49 @@ class ConversationTest(unittest.TestCase):
         # Note: in real life, we always create
         # comments via the factory to allow different factories to be
         # swapped in
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'Comment text'
-        comment1.author_username = 'Jim'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Comment text"
+        comment1.author_username = "Jim"
         conversation.addComment(comment1)
 
-        comment2 = createObject('plone.Comment')
-        comment2.text = 'Comment text'
-        comment2.author_username = 'Joe'
+        comment2 = createObject("plone.Comment")
+        comment2.text = "Comment text"
+        comment2.author_username = "Joe"
         conversation.addComment(comment2)
 
-        comment3 = createObject('plone.Comment')
-        comment3.text = 'Comment text'
-        comment3.author_username = 'Jack'
+        comment3 = createObject("plone.Comment")
+        comment3.text = "Comment text"
+        comment3.author_username = "Jack"
         new_comment3_id = conversation.addComment(comment3)
 
-        comment4 = createObject('plone.Comment')
-        comment4.text = 'Comment text'
-        comment4.author_username = 'Jack'
+        comment4 = createObject("plone.Comment")
+        comment4.text = "Comment text"
+        comment4.author_username = "Jack"
         new_comment4_id = conversation.addComment(comment4)
 
         # check if all commentators are in the commentators list
         self.assertEqual(conversation.total_comments(), 4)
-        self.assertTrue('Jim' in conversation.commentators)
-        self.assertTrue('Joe' in conversation.commentators)
-        self.assertTrue('Jack' in conversation.commentators)
+        self.assertTrue("Jim" in conversation.commentators)
+        self.assertTrue("Joe" in conversation.commentators)
+        self.assertTrue("Jack" in conversation.commentators)
 
         # remove the comment from Jack
         del conversation[new_comment3_id]
 
         # check if Jack is still in the commentators list (since
         # he had added two comments)
-        self.assertTrue('Jim' in conversation.commentators)
-        self.assertTrue('Joe' in conversation.commentators)
-        self.assertTrue('Jack' in conversation.commentators)
+        self.assertTrue("Jim" in conversation.commentators)
+        self.assertTrue("Joe" in conversation.commentators)
+        self.assertTrue("Jack" in conversation.commentators)
         self.assertEqual(conversation.total_comments(), 3)
 
         # remove the second comment from Jack
         del conversation[new_comment4_id]
 
         # check if Jack has been removed from the commentators list
-        self.assertTrue('Jim' in conversation.commentators)
-        self.assertTrue('Joe' in conversation.commentators)
-        self.assertFalse('Jack' in conversation.commentators)
+        self.assertTrue("Jim" in conversation.commentators)
+        self.assertTrue("Joe" in conversation.commentators)
+        self.assertFalse("Jack" in conversation.commentators)
         self.assertEqual(conversation.total_comments(), 2)
 
     def test_last_comment_date(self):
@@ -494,29 +486,29 @@ class ConversationTest(unittest.TestCase):
         # Note: in real life, we always create
         # comments via the factory to allow different factories to be
         # swapped in
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'Comment text'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Comment text"
         comment1.creation_date = datetime.utcnow() - timedelta(4)
         conversation.addComment(comment1)
 
-        comment2 = createObject('plone.Comment')
-        comment2.text = 'Comment text'
+        comment2 = createObject("plone.Comment")
+        comment2.text = "Comment text"
         comment2.creation_date = datetime.utcnow() - timedelta(2)
         new_comment2_id = conversation.addComment(comment2)
 
-        comment3 = createObject('plone.Comment')
-        comment3.text = 'Comment text'
+        comment3 = createObject("plone.Comment")
+        comment3.text = "Comment text"
         comment3.creation_date = datetime.utcnow() - timedelta(1)
         new_comment3_id = conversation.addComment(comment3)
 
         # check if the latest comment is exactly one day old
         self.assertTrue(
-            conversation.last_comment_date < datetime.utcnow() -
-            timedelta(hours=23, minutes=59, seconds=59),
+            conversation.last_comment_date
+            < datetime.utcnow() - timedelta(hours=23, minutes=59, seconds=59),
         )
         self.assertTrue(
-            conversation.last_comment_date >
-            datetime.utcnow() - timedelta(days=1, seconds=1),
+            conversation.last_comment_date
+            > datetime.utcnow() - timedelta(days=1, seconds=1),
         )
 
         # remove the latest comment
@@ -525,12 +517,12 @@ class ConversationTest(unittest.TestCase):
         # check if the latest comment has been updated
         # the latest comment should be exactly two days old
         self.assertTrue(
-            conversation.last_comment_date < datetime.utcnow() -
-            timedelta(days=1, hours=23, minutes=59, seconds=59),
+            conversation.last_comment_date
+            < datetime.utcnow() - timedelta(days=1, hours=23, minutes=59, seconds=59),
         )
         self.assertTrue(
-            conversation.last_comment_date > datetime.utcnow() -
-            timedelta(days=2, seconds=1),
+            conversation.last_comment_date
+            > datetime.utcnow() - timedelta(days=2, seconds=1),
         )
 
         # remove the latest comment again
@@ -539,12 +531,12 @@ class ConversationTest(unittest.TestCase):
         # check if the latest comment has been updated
         # the latest comment should be exactly four days old
         self.assertTrue(
-            conversation.last_comment_date < datetime.utcnow() -
-            timedelta(days=3, hours=23, minutes=59, seconds=59),
+            conversation.last_comment_date
+            < datetime.utcnow() - timedelta(days=3, hours=23, minutes=59, seconds=59),
         )
         self.assertTrue(
-            conversation.last_comment_date > datetime.utcnow() -
-            timedelta(days=4, seconds=2),
+            conversation.last_comment_date
+            > datetime.utcnow() - timedelta(days=4, seconds=2),
         )
 
     def test_get_comments_full(self):
@@ -572,23 +564,23 @@ class ConversationTest(unittest.TestCase):
         #    +- Comment 2_1
 
         # Create all comments
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'Comment text'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Comment text"
 
-        comment1_1 = createObject('plone.Comment')
-        comment1_1.text = 'Comment text'
+        comment1_1 = createObject("plone.Comment")
+        comment1_1.text = "Comment text"
 
-        comment1_1_1 = createObject('plone.Comment')
-        comment1_1_1.text = 'Comment text'
+        comment1_1_1 = createObject("plone.Comment")
+        comment1_1_1.text = "Comment text"
 
-        comment1_2 = createObject('plone.Comment')
-        comment1_2.text = 'Comment text'
+        comment1_2 = createObject("plone.Comment")
+        comment1_2.text = "Comment text"
 
-        comment2 = createObject('plone.Comment')
-        comment2.text = 'Comment text'
+        comment2 = createObject("plone.Comment")
+        comment2.text = "Comment text"
 
-        comment2_1 = createObject('plone.Comment')
-        comment2_1.text = 'Comment text'
+        comment2_1 = createObject("plone.Comment")
+        comment2_1.text = "Comment text"
 
         # Create the nested comment structure
         new_id_1 = conversation.addComment(comment1)
@@ -608,14 +600,17 @@ class ConversationTest(unittest.TestCase):
 
         # Get threads
 
-        self.assertEqual([
-            {'comment': comment1, 'depth': 0, 'id': new_id_1},
-            {'comment': comment1_1, 'depth': 1, 'id': new_id_1_1},
-            {'comment': comment1_1_1, 'depth': 2, 'id': new_id_1_1_1},
-            {'comment': comment1_2, 'depth': 1, 'id': new_id_1_2},
-            {'comment': comment2, 'depth': 0, 'id': new_id_2},
-            {'comment': comment2_1, 'depth': 1, 'id': new_id_2_1},
-        ], list(conversation.getThreads()))
+        self.assertEqual(
+            [
+                {"comment": comment1, "depth": 0, "id": new_id_1},
+                {"comment": comment1_1, "depth": 1, "id": new_id_1_1},
+                {"comment": comment1_1_1, "depth": 2, "id": new_id_1_1_1},
+                {"comment": comment1_2, "depth": 1, "id": new_id_1_2},
+                {"comment": comment2, "depth": 0, "id": new_id_2},
+                {"comment": comment2_1, "depth": 1, "id": new_id_2_1},
+            ],
+            list(conversation.getThreads()),
+        )
 
     def test_get_threads_batched(self):
         # TODO: test start, size, root and depth arguments to getThreads()  # noqa T000
@@ -626,16 +621,16 @@ class ConversationTest(unittest.TestCase):
         # make sure we can traverse to conversations and get a URL and path
 
         conversation = self.portal.doc1.restrictedTraverse(
-            '++conversation++default',
+            "++conversation++default",
         )
         self.assertTrue(IConversation.providedBy(conversation))
 
         self.assertEqual(
-            ('', 'plone', 'doc1', '++conversation++default'),
+            ("", "plone", "doc1", "++conversation++default"),
             conversation.getPhysicalPath(),
         )
         self.assertEqual(
-            'http://nohost/plone/doc1/++conversation++default',
+            "http://nohost/plone/doc1/++conversation++default",
             conversation.absolute_url(),
         )
 
@@ -644,7 +639,7 @@ class ConversationTest(unittest.TestCase):
         # can't be converted to int
 
         conversation = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/ThisCantBeRight',
+            "++conversation++default/ThisCantBeRight",
         )
         self.assertEqual(conversation, None)
 
@@ -658,17 +653,16 @@ class ConversationTest(unittest.TestCase):
         self.assertTrue(conversation.__parent__)
         self.assertTrue(aq_parent(conversation))
 
-        self.assertEqual(conversation.__parent__.getId(), 'doc1')
+        self.assertEqual(conversation.__parent__.getId(), "doc1")
 
     def test_discussion_item_not_in_bad_types(self):
-        self.assertFalse('Discussion Item' in BAD_TYPES)
+        self.assertFalse("Discussion Item" in BAD_TYPES)
 
     def test_no_comment(self):
         IConversation(self.portal.doc1)
         # Make sure no conversation has been created
         self.assertTrue(
-            'plone.app.discussion:conversation' not in
-            IAnnotations(self.portal.doc1),
+            "plone.app.discussion:conversation" not in IAnnotations(self.portal.doc1),
         )
 
 
@@ -677,21 +671,20 @@ class ConversationEnabledForDexterityTypesTest(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
         interface.alsoProvides(
             self.portal.REQUEST,
-            interfaces.IDiscussionLayer,
+            IDiscussionLayer,
         )
 
-        if DEXTERITY:
-            interface.alsoProvides(
-                self.portal.doc1,
-                IDexterityContent,
-            )
+        interface.alsoProvides(
+            self.portal.doc1,
+            IDexterityContent,
+        )
 
     def _makeOne(self, *args, **kw):
-        return self.portal.doc1.restrictedTraverse('@@conversation_view')
+        return self.portal.doc1.restrictedTraverse("@@conversation_view")
 
     def _globally_enable_discussion(self, value):
         registry = queryUtility(IRegistry)
@@ -699,43 +692,38 @@ class ConversationEnabledForDexterityTypesTest(unittest.TestCase):
         settings.globally_enabled = value
 
     def _enable_discussion_on_portal_type(self, portal_type, allow_discussion):
-        portal_types = getToolByName(self.portal, 'portal_types')
+        portal_types = getToolByName(self.portal, "portal_types")
         document_fti = getattr(portal_types, portal_type)
         document_fti.manage_changeProperties(allow_discussion=allow_discussion)
 
     def test_conversation_is_not_enabled_by_default(self):
-        if DEXTERITY:
-            conversation = self._makeOne(self.portal.doc1)
-            self.assertFalse(conversation.enabled())
+        conversation = self._makeOne(self.portal.doc1)
+        self.assertFalse(conversation.enabled())
 
     def test_conversation_is_not_enabled_by_default_on_portal_type(self):
-        if DEXTERITY:
-            self._globally_enable_discussion(True)
-            conversation = self._makeOne(self.portal.doc1)
-            self.assertFalse(conversation.enabled())
+        self._globally_enable_discussion(True)
+        conversation = self._makeOne(self.portal.doc1)
+        self.assertFalse(conversation.enabled())
 
     def test_conversation_needs_to_be_enabled_globally_and_for_type(self):
-        if DEXTERITY:
-            self._globally_enable_discussion(True)
-            self._enable_discussion_on_portal_type('Document', True)
-            conversation = self._makeOne(self.portal.doc1)
-            self.assertTrue(conversation.enabled())
+        self._globally_enable_discussion(True)
+        self._enable_discussion_on_portal_type("Document", True)
+        conversation = self._makeOne(self.portal.doc1)
+        self.assertTrue(conversation.enabled())
 
     def test_disable_discussion(self):
-        if DEXTERITY:
-            self._globally_enable_discussion(True)
-            self._enable_discussion_on_portal_type('Document', True)
-            self.portal.doc1.allow_discussion = False
-            conversation = self._makeOne(self.portal.doc1)
-            self.assertFalse(conversation.enabled())
+        self._globally_enable_discussion(True)
+        self._enable_discussion_on_portal_type("Document", True)
+        self.portal.doc1.allow_discussion = False
+        conversation = self._makeOne(self.portal.doc1)
+        self.assertFalse(conversation.enabled())
 
     def test_enable_discussion(self):
-        if DEXTERITY:
-            self._globally_enable_discussion(True)
-            self._enable_discussion_on_portal_type('Document', True)
-            self.portal.doc1.allow_discussion = True
-            conversation = self._makeOne(self.portal.doc1)
-            self.assertTrue(conversation.enabled())
+        self._globally_enable_discussion(True)
+        self._enable_discussion_on_portal_type("Document", True)
+        self.portal.doc1.allow_discussion = True
+        conversation = self._makeOne(self.portal.doc1)
+        self.assertTrue(conversation.enabled())
 
 
 class RepliesTest(unittest.TestCase):
@@ -745,11 +733,11 @@ class RepliesTest(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
 
         workflow = self.portal.portal_workflow
-        workflow.doActionFor(self.portal.doc1, 'publish')
+        workflow.doActionFor(self.portal.doc1, "publish")
 
     def test_add_comment(self):
         # Add comments to a ConversationReplies adapter
@@ -760,8 +748,8 @@ class RepliesTest(unittest.TestCase):
 
         replies = IReplies(conversation)
 
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
 
         new_id = replies.addComment(comment)
 
@@ -787,8 +775,8 @@ class RepliesTest(unittest.TestCase):
         replies = IReplies(conversation)
 
         # Add a comment.
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
 
         new_id = replies.addComment(comment)
 
@@ -826,39 +814,39 @@ class RepliesTest(unittest.TestCase):
         #    +- Comment 2_1
 
         # Create all comments
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'Comment text'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Comment text"
 
-        comment1_1 = createObject('plone.Comment')
-        comment1_1.text = 'Comment text'
+        comment1_1 = createObject("plone.Comment")
+        comment1_1.text = "Comment text"
 
-        comment1_1_1 = createObject('plone.Comment')
-        comment1_1_1.text = 'Comment text'
+        comment1_1_1 = createObject("plone.Comment")
+        comment1_1_1.text = "Comment text"
 
-        comment1_2 = createObject('plone.Comment')
-        comment1_2.text = 'Comment text'
+        comment1_2 = createObject("plone.Comment")
+        comment1_2.text = "Comment text"
 
-        comment2 = createObject('plone.Comment')
-        comment2.text = 'Comment text'
+        comment2 = createObject("plone.Comment")
+        comment2.text = "Comment text"
 
-        comment2_1 = createObject('plone.Comment')
-        comment2_1.text = 'Comment text'
+        comment2_1 = createObject("plone.Comment")
+        comment2_1.text = "Comment text"
 
         # Create the nested comment structure
         new_id_1 = replies.addComment(comment1)
         comment1 = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id_1),
+            f"++conversation++default/{new_id_1}",
         )
         replies_to_comment1 = IReplies(comment1)
         new_id_2 = replies.addComment(comment2)
         comment2 = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id_2),
+            f"++conversation++default/{new_id_2}",
         )
         replies_to_comment2 = IReplies(comment2)
 
         new_id_1_1 = replies_to_comment1.addComment(comment1_1)
         comment1_1 = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id_1_1),
+            f"++conversation++default/{new_id_1_1}",
         )
         replies_to_comment1_1 = IReplies(comment1_1)
         replies_to_comment1_1.addComment(comment1_1_1)
diff --git a/plone/app/discussion/tests/test_events.py b/plone/app/discussion/tests/test_events.py
index 3742c76..a6cc1cd 100644
--- a/plone/app/discussion/tests/test_events.py
+++ b/plone/app/discussion/tests/test_events.py
@@ -1,7 +1,6 @@
-# -*- coding: utf-8 -*-
-from plone.app.discussion.interfaces import IConversation
-from plone.app.discussion.interfaces import IReplies
-from plone.app.discussion.testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING  # noqa
+from ..interfaces import IConversation
+from ..interfaces import IReplies
+from ..testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 from plone.app.testing import setRoles
 from plone.app.testing import TEST_USER_ID
 from Zope2.App import zcml
@@ -18,9 +17,9 @@ import unittest
 #
 
 
-class EventsRegistry(object):
-    """ Fake registry to be used while testing discussion events
-    """
+class EventsRegistry:
+    """Fake registry to be used while testing discussion events"""
+
     commentAdded = False
     commentModified = False
     commentRemoved = False
@@ -28,6 +27,7 @@ class EventsRegistry(object):
     replyModified = False
     replyRemoved = False
 
+
 #
 # Fake event handlers
 #
@@ -63,19 +63,19 @@ def reply_removed(doc, evt):
 
 
 class CommentEventsTest(unittest.TestCase):
-    """ Test custom comments events
-    """
+    """Test custom comments events"""
+
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
 
         # Setup sandbox
-        self.portal = self.layer['portal']
-        self.request = self.layer['request']
+        self.portal = self.layer["portal"]
+        self.request = self.layer["request"]
         self.registry = EventsRegistry
 
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
-        self.document = self.portal['doc1']
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
+        self.document = self.portal["doc1"]
 
         #
         # Subscribers
@@ -104,23 +104,23 @@ class CommentEventsTest(unittest.TestCase):
 
          </configure>
         """
-        zcml.load_config('configure.zcml', Products.Five)
+        zcml.load_config("configure.zcml", Products.Five)
         zcml.load_string(configure)
 
     def test_addEvent(self):
         self.assertFalse(self.registry.commentAdded)
-        comment = createObject('plone.Comment')
+        comment = createObject("plone.Comment")
         conversation = IConversation(self.document)
         conversation.addComment(comment)
         self.assertTrue(self.registry.commentAdded)
 
     def test_modifyEvent(self):
         self.assertFalse(self.registry.commentModified)
-        comment = createObject('plone.Comment')
+        comment = createObject("plone.Comment")
         conversation = IConversation(self.document)
         new_id = conversation.addComment(comment)
         comment = self.document.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id),
+            f"++conversation++default/{new_id}",
         )
         comment.text = "foo"
         notify(ObjectModifiedEvent(comment))
@@ -128,7 +128,7 @@ class CommentEventsTest(unittest.TestCase):
 
     def test_removedEvent(self):
         self.assertFalse(self.registry.commentRemoved)
-        comment = createObject('plone.Comment')
+        comment = createObject("plone.Comment")
         conversation = IConversation(self.document)
         cid = conversation.addComment(comment)
         del conversation[cid]
@@ -136,17 +136,17 @@ class CommentEventsTest(unittest.TestCase):
 
 
 class RepliesEventsTest(unittest.TestCase):
-    """ Test custom replies events
-    """
+    """Test custom replies events"""
+
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        self.request = self.layer['request']
+        self.portal = self.layer["portal"]
+        self.request = self.layer["request"]
         self.registry = EventsRegistry
 
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
-        self.document = self.portal['doc1']
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
+        self.document = self.portal["doc1"]
 
         #
         # Subscribers
@@ -175,7 +175,7 @@ class RepliesEventsTest(unittest.TestCase):
 
          </configure>
         """
-        zcml.load_config('configure.zcml', Products.Five)
+        zcml.load_config("configure.zcml", Products.Five)
         zcml.load_string(configure)
 
     def test_addEvent(self):
@@ -184,15 +184,15 @@ class RepliesEventsTest(unittest.TestCase):
         conversation = IConversation(self.document)
         replies = IReplies(conversation)
 
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         new_id = replies.addComment(comment)
         comment = self.document.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id),
+            f"++conversation++default/{new_id}",
         )
 
-        re_comment = createObject('plone.Comment')
-        re_comment.text = 'Comment text'
+        re_comment = createObject("plone.Comment")
+        re_comment.text = "Comment text"
 
         replies = IReplies(comment)
         replies.addComment(re_comment)
@@ -204,14 +204,14 @@ class RepliesEventsTest(unittest.TestCase):
 
         conversation = IConversation(self.document)
         replies = IReplies(conversation)
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         comment_id = replies.addComment(comment)
         comment = self.document.restrictedTraverse(
-            '++conversation++default/{0}'.format(comment_id),
+            f"++conversation++default/{comment_id}",
         )
-        re_comment = createObject('plone.Comment')
-        re_comment.text = 'Comment text'
+        re_comment = createObject("plone.Comment")
+        re_comment.text = "Comment text"
         replies = IReplies(comment)
         new_id = replies.addComment(re_comment)
         reply = replies[new_id]
@@ -225,15 +225,15 @@ class RepliesEventsTest(unittest.TestCase):
         conversation = IConversation(self.portal.doc1)
         replies = IReplies(conversation)
 
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         new_id = replies.addComment(comment)
         comment = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id),
+            f"++conversation++default/{new_id}",
         )
 
-        re_comment = createObject('plone.Comment')
-        re_comment.text = 'Comment text'
+        re_comment = createObject("plone.Comment")
+        re_comment.text = "Comment text"
         replies = IReplies(comment)
         new_re_id = replies.addComment(re_comment)
 
diff --git a/plone/app/discussion/tests/test_functional.py b/plone/app/discussion/tests/test_functional.py
index 14db437..995016e 100644
--- a/plone/app/discussion/tests/test_functional.py
+++ b/plone/app/discussion/tests/test_functional.py
@@ -1,9 +1,8 @@
-# -*- coding: utf-8 -*-
 """Functional Doctests for plone.app.discussion.
 
    These test are only triggered when Plone 4 (and plone.testing) is installed.
 """
-from plone.app.discussion.testing import PLONE_APP_DISCUSSION_FUNCTIONAL_TESTING  # noqa
+from ..testing import PLONE_APP_DISCUSSION_FUNCTIONAL_TESTING  # noqa
 from plone.testing import layered
 
 import doctest
@@ -12,29 +11,29 @@ import unittest
 
 
 optionflags = (
-    doctest.ELLIPSIS |
-    doctest.NORMALIZE_WHITESPACE |
-    doctest.REPORT_ONLY_FIRST_FAILURE
+    doctest.ELLIPSIS | doctest.NORMALIZE_WHITESPACE | doctest.REPORT_ONLY_FIRST_FAILURE
 )
 normal_testfiles = [
-    'functional_test_comments.txt',
-    'functional_test_comment_review_workflow.txt',
+    "functional_test_comments.txt",
+    "functional_test_comment_review_workflow.txt",
 ]
 
 
 def test_suite():
     suite = unittest.TestSuite()
-    suite.addTests([
-        layered(
-            doctest.DocFileSuite(
-                test,
-                optionflags=optionflags,
-                globs={
-                    'pprint': pprint.pprint,
-                }
-            ),
-            layer=PLONE_APP_DISCUSSION_FUNCTIONAL_TESTING,
-        )
-        for test in normal_testfiles
-    ])
+    suite.addTests(
+        [
+            layered(
+                doctest.DocFileSuite(
+                    test,
+                    optionflags=optionflags,
+                    globs={
+                        "pprint": pprint.pprint,
+                    },
+                ),
+                layer=PLONE_APP_DISCUSSION_FUNCTIONAL_TESTING,
+            )
+            for test in normal_testfiles
+        ]
+    )
     return suite
diff --git a/plone/app/discussion/tests/test_indexers.py b/plone/app/discussion/tests/test_indexers.py
index 56efebc..b1b30f1 100644
--- a/plone/app/discussion/tests/test_indexers.py
+++ b/plone/app/discussion/tests/test_indexers.py
@@ -1,11 +1,10 @@
-# -*- coding: utf-8 -*-
 """Test for the plone.app.discussion indexers
 """
-from DateTime import DateTime
+from .. import catalog
+from ..interfaces import IConversation
+from ..testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING  # noqa
 from datetime import datetime
-from plone.app.discussion import catalog
-from plone.app.discussion.interfaces import IConversation
-from plone.app.discussion.testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING  # noqa
+from DateTime import DateTime
 from plone.app.testing import setRoles
 from plone.app.testing import TEST_USER_ID
 from plone.indexer.delegate import DelegatingIndexerFactory
@@ -26,41 +25,40 @@ sed diam voluptua. At [...]"""
 
 
 class ConversationIndexersTest(unittest.TestCase):
-    """Conversation Indexer Tests
-    """
+    """Conversation Indexer Tests"""
 
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
 
         workflow = self.portal.portal_workflow
-        workflow.doActionFor(self.portal.doc1, 'publish')
+        workflow.doActionFor(self.portal.doc1, "publish")
 
         # Create a conversation.
         conversation = IConversation(self.portal.doc1)
 
-        comment1 = createObject('plone.Comment')
-        comment1.text = 'Comment Text'
-        comment1.creator = 'jim'
-        comment1.author_username = 'Jim'
+        comment1 = createObject("plone.Comment")
+        comment1.text = "Comment Text"
+        comment1.creator = "jim"
+        comment1.author_username = "Jim"
         comment1.creation_date = datetime(2006, 9, 17, 14, 18, 12)
         comment1.modification_date = datetime(2006, 9, 17, 14, 18, 12)
         self.new_id1 = conversation.addComment(comment1)
 
-        comment2 = createObject('plone.Comment')
-        comment2.text = 'Comment Text'
-        comment2.creator = 'emma'
-        comment2.author_username = 'Emma'
+        comment2 = createObject("plone.Comment")
+        comment2.text = "Comment Text"
+        comment2.creator = "emma"
+        comment2.author_username = "Emma"
         comment2.creation_date = datetime(2007, 12, 13, 4, 18, 12)
         comment2.modification_date = datetime(2007, 12, 13, 4, 18, 12)
         self.new_id2 = conversation.addComment(comment2)
 
-        comment3 = createObject('plone.Comment')
-        comment3.text = 'Comment Text'
-        comment3.creator = 'lukas'
-        comment3.author_username = 'Lukas'
+        comment3 = createObject("plone.Comment")
+        comment3.text = "Comment Text"
+        comment3.creator = "lukas"
+        comment3.author_username = "Lukas"
         comment3.creation_date = datetime(2009, 4, 12, 11, 12, 12)
         comment3.modification_date = datetime(2009, 4, 12, 11, 12, 12)
         self.new_id3 = conversation.addComment(comment3)
@@ -68,10 +66,12 @@ class ConversationIndexersTest(unittest.TestCase):
         self.conversation = conversation
 
     def test_conversation_total_comments(self):
-        self.assertTrue(isinstance(
-            catalog.total_comments,
-            DelegatingIndexerFactory,
-        ))
+        self.assertTrue(
+            isinstance(
+                catalog.total_comments,
+                DelegatingIndexerFactory,
+            )
+        )
         self.assertEqual(catalog.total_comments(self.portal.doc1)(), 3)
         del self.conversation[self.new_id1]
         self.assertEqual(catalog.total_comments(self.portal.doc1)(), 2)
@@ -80,10 +80,12 @@ class ConversationIndexersTest(unittest.TestCase):
         self.assertEqual(catalog.total_comments(self.portal.doc1)(), 0)
 
     def test_conversation_last_comment_date(self):
-        self.assertTrue(isinstance(
-            catalog.last_comment_date,
-            DelegatingIndexerFactory,
-        ))
+        self.assertTrue(
+            isinstance(
+                catalog.last_comment_date,
+                DelegatingIndexerFactory,
+            )
+        )
         self.assertEqual(
             catalog.last_comment_date(self.portal.doc1)(),
             datetime(2009, 4, 12, 11, 12, 12),
@@ -110,8 +112,8 @@ class CommentIndexersTest(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
 
         # Create a conversation. In this case we doesn't assign it to an
         # object, as we just want to check the Conversation object API.
@@ -120,10 +122,10 @@ class CommentIndexersTest(unittest.TestCase):
         # Add a comment. Note: in real life, we always create comments via the
         # factory to allow different factories to be swapped in
 
-        comment = createObject('plone.Comment')
-        comment.text = 'Lorem ipsum dolor sit amet.'
-        comment.creator = 'jim'
-        comment.author_name = 'Jim'
+        comment = createObject("plone.Comment")
+        comment.text = "Lorem ipsum dolor sit amet."
+        comment.creator = "jim"
+        comment.author_name = "Jim"
         comment.creation_date = datetime(2006, 9, 17, 14, 18, 12)
         comment.modification_date = datetime(2008, 3, 12, 7, 32, 52)
 
@@ -132,60 +134,61 @@ class CommentIndexersTest(unittest.TestCase):
         self.conversation = conversation
 
     def test_title(self):
-        self.assertEqual(catalog.title(self.comment)(), 'Jim on Document 1')
+        self.assertEqual(catalog.title(self.comment)(), "Jim on Document 1")
         self.assertTrue(isinstance(catalog.title, DelegatingIndexerFactory))
 
     def test_description(self):
         self.assertEqual(
             catalog.description(self.comment)(),
-            'Lorem ipsum dolor sit amet.',
+            "Lorem ipsum dolor sit amet.",
         )
-        self.assertTrue(
-            isinstance(catalog.description, DelegatingIndexerFactory))
+        self.assertTrue(isinstance(catalog.description, DelegatingIndexerFactory))
 
     def test_description_long(self):
         # Create a 50 word comment and make sure the description returns
         # only the first 25 words
-        comment_long = createObject('plone.Comment')
-        comment_long.title = 'Long Comment'
+        comment_long = createObject("plone.Comment")
+        comment_long.title = "Long Comment"
         comment_long.text = LONG_TEXT
 
         self.conversation.addComment(comment_long)
         self.assertEqual(
             catalog.description(comment_long)(),
-            LONG_TEXT_CUT.replace('\n', ' '),
+            LONG_TEXT_CUT.replace("\n", " "),
         )
 
     def test_dates(self):
         # Test if created, modified, effective etc. are set correctly
         self.assertEqual(
             catalog.created(self.comment)(),
-            DateTime(2006, 9, 17, 14, 18, 12, 'GMT'),
+            DateTime(2006, 9, 17, 14, 18, 12, "GMT"),
         )
         self.assertEqual(
             catalog.effective(self.comment)(),
-            DateTime(2006, 9, 17, 14, 18, 12, 'GMT'),
+            DateTime(2006, 9, 17, 14, 18, 12, "GMT"),
         )
         self.assertEqual(
             catalog.modified(self.comment)(),
-            DateTime(2008, 3, 12, 7, 32, 52, 'GMT'),
+            DateTime(2008, 3, 12, 7, 32, 52, "GMT"),
         )
 
     def test_searchable_text(self):
         # Test if searchable text is a concatenation of title and comment text
         self.assertEqual(
             catalog.searchable_text(self.comment)(),
-            ('Lorem ipsum dolor sit amet.'),
+            ("Lorem ipsum dolor sit amet."),
+        )
+        self.assertTrue(
+            isinstance(
+                catalog.searchable_text,
+                DelegatingIndexerFactory,
+            )
         )
-        self.assertTrue(isinstance(
-            catalog.searchable_text,
-            DelegatingIndexerFactory,
-        ))
 
     def test_creator(self):
-        self.assertEqual(catalog.creator(self.comment)(), ('jim'))
+        self.assertEqual(catalog.creator(self.comment)(), ("jim"))
 
     def test_in_response_to(self):
         # make sure in_response_to returns the title or id of the content
         # object the comment was added to
-        self.assertEqual(catalog.in_response_to(self.comment)(), 'Document 1')
+        self.assertEqual(catalog.in_response_to(self.comment)(), "Document 1")
diff --git a/plone/app/discussion/tests/test_moderation_multiple_state_view.py b/plone/app/discussion/tests/test_moderation_multiple_state_view.py
index 72b1db0..6a12a72 100644
--- a/plone/app/discussion/tests/test_moderation_multiple_state_view.py
+++ b/plone/app/discussion/tests/test_moderation_multiple_state_view.py
@@ -1,11 +1,10 @@
-# -*- coding: utf-8 -*-
-from plone.app.discussion.browser.moderation import BulkActionsView
-from plone.app.discussion.browser.moderation import DeleteComment
-from plone.app.discussion.browser.moderation import CommentTransition
-from plone.app.discussion.browser.moderation import View
-from plone.app.discussion.interfaces import IConversation
-from plone.app.discussion.interfaces import IDiscussionSettings
-from plone.app.discussion.testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING  # noqa
+from ..browser.moderation import BulkActionsView
+from ..browser.moderation import CommentTransition
+from ..browser.moderation import DeleteComment
+from ..browser.moderation import View
+from ..interfaces import IConversation
+from ..interfaces import IDiscussionSettings
+from ..testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 from plone.app.testing import setRoles
 from plone.app.testing import TEST_USER_ID
 from plone.registry.interfaces import IRegistry
@@ -21,59 +20,57 @@ class ModerationBulkActionsViewTest(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.app = self.layer['app']
-        self.portal = self.layer['portal']
-        self.request = self.layer['request']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
-        self.wf = getToolByName(self.portal,
-                                'portal_workflow',
-                                None)
+        self.app = self.layer["app"]
+        self.portal = self.layer["portal"]
+        self.request = self.layer["request"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
+        self.wf = getToolByName(self.portal, "portal_workflow", None)
         self.context = self.portal
         self.portal.portal_workflow.setChainForPortalTypes(
-            ('Discussion Item',),
-            'comment_review_workflow',
+            ("Discussion Item",),
+            "comment_review_workflow",
         )
         self.wf_tool = self.portal.portal_workflow
         # Add a conversation with three comments
         conversation = IConversation(self.portal.doc1)
-        comment1 = createObject('plone.Comment')
-        comment1.title = 'Comment 1'
-        comment1.text = 'Comment text'
-        comment1.Creator = 'Jim'
+        comment1 = createObject("plone.Comment")
+        comment1.title = "Comment 1"
+        comment1.text = "Comment text"
+        comment1.Creator = "Jim"
         new_id_1 = conversation.addComment(comment1)
         self.comment1 = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id_1),
+            f"++conversation++default/{new_id_1}",
         )
-        comment2 = createObject('plone.Comment')
-        comment2.title = 'Comment 2'
-        comment2.text = 'Comment text'
-        comment2.Creator = 'Joe'
+        comment2 = createObject("plone.Comment")
+        comment2.title = "Comment 2"
+        comment2.text = "Comment text"
+        comment2.Creator = "Joe"
         new_id_2 = conversation.addComment(comment2)
         self.comment2 = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id_2),
+            f"++conversation++default/{new_id_2}",
         )
-        comment3 = createObject('plone.Comment')
-        comment3.title = 'Comment 3'
-        comment3.text = 'Comment text'
-        comment3.Creator = 'Emma'
+        comment3 = createObject("plone.Comment")
+        comment3.title = "Comment 3"
+        comment3.text = "Comment text"
+        comment3.Creator = "Emma"
         new_id_3 = conversation.addComment(comment3)
         self.comment3 = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id_3),
+            f"++conversation++default/{new_id_3}",
         )
         self.conversation = conversation
 
     def test_default_bulkaction(self):
         # Make sure no error is raised when no bulk actions has been supplied
-        self.request.set('form.select.BulkAction', '-1')
-        self.request.set('paths', ['/'.join(self.comment1.getPhysicalPath())])
+        self.request.set("form.select.BulkAction", "-1")
+        self.request.set("paths", ["/".join(self.comment1.getPhysicalPath())])
 
         view = BulkActionsView(self.portal, self.request)
 
         self.assertFalse(view())
 
     def test_publish(self):
-        self.request.set('form.select.BulkAction', 'publish')
-        self.request.set('paths', ['/'.join(self.comment1.getPhysicalPath())])
+        self.request.set("form.select.BulkAction", "publish")
+        self.request.set("paths", ["/".join(self.comment1.getPhysicalPath())])
         view = BulkActionsView(self.portal, self.request)
 
         view()
@@ -81,16 +78,16 @@ class ModerationBulkActionsViewTest(unittest.TestCase):
         # Count published comments
         published_comments = 0
         for r in self.conversation.getThreads():
-            comment_obj = r['comment']
-            workflow_status = self.wf.getInfoFor(comment_obj, 'review_state')
-            if workflow_status == 'published':
+            comment_obj = r["comment"]
+            workflow_status = self.wf.getInfoFor(comment_obj, "review_state")
+            if workflow_status == "published":
                 published_comments += 1
         # Make sure the comment has been published
         self.assertEqual(published_comments, 1)
 
     def test_mark_as_spam(self):
-        self.request.set('form.select.BulkAction', 'mark_as_spam')
-        self.request.set('paths', ['/'.join(self.comment1.getPhysicalPath())])
+        self.request.set("form.select.BulkAction", "mark_as_spam")
+        self.request.set("paths", ["/".join(self.comment1.getPhysicalPath())])
 
         view = BulkActionsView(self.portal, self.request)
 
@@ -99,9 +96,9 @@ class ModerationBulkActionsViewTest(unittest.TestCase):
         # Count spam comments
         spam_comments = 0
         for r in self.conversation.getThreads():
-            comment_obj = r['comment']
-            workflow_status = self.wf.getInfoFor(comment_obj, 'review_state')
-            if workflow_status == 'spam':
+            comment_obj = r["comment"]
+            workflow_status = self.wf.getInfoFor(comment_obj, "review_state")
+            if workflow_status == "spam":
                 spam_comments += 1
         # Make sure the comment has been marked as spam
         self.assertEqual(spam_comments, 1)
@@ -110,9 +107,14 @@ class ModerationBulkActionsViewTest(unittest.TestCase):
         # Initially we have three comments
         self.assertEqual(len(self.conversation.objectIds()), 3)
         # Delete two comments with bulk actions
-        self.request.set('form.select.BulkAction', 'delete')
-        self.request.set('paths', ['/'.join(self.comment1.getPhysicalPath()),
-                                   '/'.join(self.comment3.getPhysicalPath())])
+        self.request.set("form.select.BulkAction", "delete")
+        self.request.set(
+            "paths",
+            [
+                "/".join(self.comment1.getPhysicalPath()),
+                "/".join(self.comment3.getPhysicalPath()),
+            ],
+        )
         view = BulkActionsView(self.app, self.request)
 
         view()
diff --git a/plone/app/discussion/tests/test_moderation_view.py b/plone/app/discussion/tests/test_moderation_view.py
index 76eddb3..639eaa3 100644
--- a/plone/app/discussion/tests/test_moderation_view.py
+++ b/plone/app/discussion/tests/test_moderation_view.py
@@ -1,11 +1,10 @@
-# -*- coding: utf-8 -*-
-from plone.app.discussion.browser.moderation import BulkActionsView
-from plone.app.discussion.browser.moderation import DeleteComment
-from plone.app.discussion.browser.moderation import CommentTransition
-from plone.app.discussion.browser.moderation import View
-from plone.app.discussion.interfaces import IConversation
-from plone.app.discussion.interfaces import IDiscussionSettings
-from plone.app.discussion.testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING  # noqa
+from ..browser.moderation import BulkActionsView
+from ..browser.moderation import CommentTransition
+from ..browser.moderation import DeleteComment
+from ..browser.moderation import View
+from ..interfaces import IConversation
+from ..interfaces import IDiscussionSettings
+from ..testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 from plone.app.testing import setRoles
 from plone.app.testing import TEST_USER_ID
 from plone.registry.interfaces import IRegistry
@@ -21,37 +20,37 @@ class ModerationViewTest(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.app = self.layer['app']
-        self.portal = self.layer['portal']
-        self.request = self.layer['request']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
-        self.portal_discussion = getToolByName(self.portal,
-                                               'portal_discussion',
-                                               None)
-        self.membership_tool = getToolByName(self.portal,
-                                             'portal_membership')
+        self.app = self.layer["app"]
+        self.portal = self.layer["portal"]
+        self.request = self.layer["request"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
+        self.portal_discussion = getToolByName(self.portal, "portal_discussion", None)
+        self.membership_tool = getToolByName(self.portal, "portal_membership")
         self.memberdata = self.portal.portal_memberdata
         request = self.app.REQUEST
-        context = getattr(self.portal, 'doc1')
+        context = getattr(self.portal, "doc1")
         self.view = View(context, request)
         self.portal.portal_workflow.setChainForPortalTypes(
-            ('Discussion Item',), 'comment_review_workflow')
+            ("Discussion Item",), "comment_review_workflow"
+        )
         self.wf_tool = self.portal.portal_workflow
 
     def test_moderation_enabled(self):
         """Make sure that moderation_enabled returns true if the comment
-           workflow implements a 'pending' state.
+        workflow implements a 'pending' state.
         """
         # If workflow is not set, enabled must return False
-        self.wf_tool.setChainForPortalTypes(('Discussion Item',), ())
+        self.wf_tool.setChainForPortalTypes(("Discussion Item",), ())
         self.assertEqual(self.view.moderation_enabled(), False)
         # The comment_one_state_workflow does not have a 'pending' state
-        self.wf_tool.setChainForPortalTypes(('Discussion Item',),
-                                            ('comment_one_state_workflow,'))
+        self.wf_tool.setChainForPortalTypes(
+            ("Discussion Item",), ("comment_one_state_workflow,")
+        )
         self.assertEqual(self.view.moderation_enabled(), False)
         # The comment_review_workflow does have a 'pending' state
-        self.wf_tool.setChainForPortalTypes(('Discussion Item',),
-                                            ('comment_review_workflow,'))
+        self.wf_tool.setChainForPortalTypes(
+            ("Discussion Item",), ("comment_review_workflow,")
+        )
         self.assertEqual(self.view.moderation_enabled(), True)
 
 
@@ -60,59 +59,57 @@ class ModerationBulkActionsViewTest(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.app = self.layer['app']
-        self.portal = self.layer['portal']
-        self.request = self.layer['request']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
-        self.wf = getToolByName(self.portal,
-                                'portal_workflow',
-                                None)
+        self.app = self.layer["app"]
+        self.portal = self.layer["portal"]
+        self.request = self.layer["request"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
+        self.wf = getToolByName(self.portal, "portal_workflow", None)
         self.context = self.portal
         self.portal.portal_workflow.setChainForPortalTypes(
-            ('Discussion Item',),
-            'comment_review_workflow',
+            ("Discussion Item",),
+            "comment_review_workflow",
         )
         self.wf_tool = self.portal.portal_workflow
         # Add a conversation with three comments
         conversation = IConversation(self.portal.doc1)
-        comment1 = createObject('plone.Comment')
-        comment1.title = 'Comment 1'
-        comment1.text = 'Comment text'
-        comment1.Creator = 'Jim'
+        comment1 = createObject("plone.Comment")
+        comment1.title = "Comment 1"
+        comment1.text = "Comment text"
+        comment1.Creator = "Jim"
         new_id_1 = conversation.addComment(comment1)
         self.comment1 = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id_1),
+            f"++conversation++default/{new_id_1}",
         )
-        comment2 = createObject('plone.Comment')
-        comment2.title = 'Comment 2'
-        comment2.text = 'Comment text'
-        comment2.Creator = 'Joe'
+        comment2 = createObject("plone.Comment")
+        comment2.title = "Comment 2"
+        comment2.text = "Comment text"
+        comment2.Creator = "Joe"
         new_id_2 = conversation.addComment(comment2)
         self.comment2 = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id_2),
+            f"++conversation++default/{new_id_2}",
         )
-        comment3 = createObject('plone.Comment')
-        comment3.title = 'Comment 3'
-        comment3.text = 'Comment text'
-        comment3.Creator = 'Emma'
+        comment3 = createObject("plone.Comment")
+        comment3.title = "Comment 3"
+        comment3.text = "Comment text"
+        comment3.Creator = "Emma"
         new_id_3 = conversation.addComment(comment3)
         self.comment3 = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(new_id_3),
+            f"++conversation++default/{new_id_3}",
         )
         self.conversation = conversation
 
     def test_default_bulkaction(self):
         # Make sure no error is raised when no bulk actions has been supplied
-        self.request.set('form.select.BulkAction', '-1')
-        self.request.set('paths', ['/'.join(self.comment1.getPhysicalPath())])
+        self.request.set("form.select.BulkAction", "-1")
+        self.request.set("paths", ["/".join(self.comment1.getPhysicalPath())])
 
         view = BulkActionsView(self.portal, self.request)
 
         self.assertFalse(view())
 
     def test_publish(self):
-        self.request.set('form.select.BulkAction', 'publish')
-        self.request.set('paths', ['/'.join(self.comment1.getPhysicalPath())])
+        self.request.set("form.select.BulkAction", "publish")
+        self.request.set("paths", ["/".join(self.comment1.getPhysicalPath())])
         view = BulkActionsView(self.portal, self.request)
 
         view()
@@ -120,9 +117,9 @@ class ModerationBulkActionsViewTest(unittest.TestCase):
         # Count published comments
         published_comments = 0
         for r in self.conversation.getThreads():
-            comment_obj = r['comment']
-            workflow_status = self.wf.getInfoFor(comment_obj, 'review_state')
-            if workflow_status == 'published':
+            comment_obj = r["comment"]
+            workflow_status = self.wf.getInfoFor(comment_obj, "review_state")
+            if workflow_status == "published":
                 published_comments += 1
         # Make sure the comment has been published
         self.assertEqual(published_comments, 1)
@@ -131,9 +128,14 @@ class ModerationBulkActionsViewTest(unittest.TestCase):
         # Initially we have three comments
         self.assertEqual(len(self.conversation.objectIds()), 3)
         # Delete two comments with bulk actions
-        self.request.set('form.select.BulkAction', 'delete')
-        self.request.set('paths', ['/'.join(self.comment1.getPhysicalPath()),
-                                   '/'.join(self.comment3.getPhysicalPath())])
+        self.request.set("form.select.BulkAction", "delete")
+        self.request.set(
+            "paths",
+            [
+                "/".join(self.comment1.getPhysicalPath()),
+                "/".join(self.comment3.getPhysicalPath()),
+            ],
+        )
         view = BulkActionsView(self.app, self.request)
 
         view()
@@ -151,41 +153,41 @@ class RedirectionTest(unittest.TestCase):
 
     def setUp(self):
         # Update settings.
-        self.portal = self.layer['portal']
-        self.request = self.layer['request']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        self.portal = self.layer["portal"]
+        self.request = self.layer["request"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
         # applyProfile(self.portal, 'plone.app.discussion:default')
         registry = queryUtility(IRegistry)
         settings = registry.forInterface(IDiscussionSettings)
         settings.globally_enabled = True
         self.portal.portal_workflow.setChainForPortalTypes(
-            ('Discussion Item',),
-            ('comment_review_workflow',),
+            ("Discussion Item",),
+            ("comment_review_workflow",),
         )
         # Create page plus comment.
         self.portal.invokeFactory(
-            id='page',
-            title='Page 1',
-            type_name='Document',
+            id="page",
+            title="Page 1",
+            type_name="Document",
         )
         self.page = self.portal.page
         self.conversation = IConversation(self.page)
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         self.comment_id = self.conversation.addComment(comment)
         self.comment = list(self.conversation.getComments())[0]
 
     def test_regression(self):
         page_url = self.page.absolute_url()
-        self.request['HTTP_REFERER'] = page_url
+        self.request["HTTP_REFERER"] = page_url
         for Klass in (DeleteComment, CommentTransition):
             view = Klass(self.comment, self.request)
             view.__parent__ = self.comment
             self.assertEqual(page_url, view())
 
     def test_valid_next_url(self):
-        self.request['HTTP_REFERER'] = 'http://attacker.com'
+        self.request["HTTP_REFERER"] = "http://attacker.com"
         for Klass in (DeleteComment, CommentTransition):
             view = Klass(self.comment, self.request)
             view.__parent__ = self.comment
-            self.assertNotEqual('http://attacker.com', view())
+            self.assertNotEqual("http://attacker.com", view())
diff --git a/plone/app/discussion/tests/test_notifications.py b/plone/app/discussion/tests/test_notifications.py
index 13f9f6d..305c90e 100644
--- a/plone/app/discussion/tests/test_notifications.py
+++ b/plone/app/discussion/tests/test_notifications.py
@@ -1,13 +1,14 @@
-# -*- coding: utf-8 -*-
+from ..interfaces import IConversation
+from ..testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 from Acquisition import aq_base
-from plone.app.discussion.interfaces import IConversation
-from plone.app.discussion.testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING  # noqa
+from persistent.list import PersistentList
 from plone.app.testing import setRoles
 from plone.app.testing import TEST_USER_ID
+from plone.base.interfaces import IMailSchema
 from plone.registry.interfaces import IRegistry
-from Products.CMFPlone.interfaces import IMailSchema
-from Products.CMFPlone.tests.utils import MockMailHost
 from Products.MailHost.interfaces import IMailHost
+from Products.MailHost.MailHost import _mungeHeaders
+from Products.MailHost.MailHost import MailBase
 from zope.component import createObject
 from zope.component import getSiteManager
 from zope.component import getUtility
@@ -16,50 +17,85 @@ from zope.component import queryUtility
 import unittest
 
 
+class MockMailHost(MailBase):
+    """A MailHost that collects messages instead of sending them."""
+
+    def __init__(self, id):
+        self.reset()
+
+    def reset(self):
+        self.messages = PersistentList()
+
+    def _send(self, mfrom, mto, messageText, immediate=False):
+        """Send the message"""
+        self.messages.append(messageText)
+
+    def send(
+        self,
+        messageText,
+        mto=None,
+        mfrom=None,
+        subject=None,
+        encode=None,
+        immediate=False,
+        charset=None,
+        msg_type=None,
+    ):
+        """send *messageText* modified by the other parameters.
+
+        *messageText* can either be an ``email.message.Message``
+        or a string.
+        Note that Products.MailHost 4.10 had changes here.
+        """
+        msg, mto, mfrom = _mungeHeaders(
+            messageText, mto, mfrom, subject, charset, msg_type, encode
+        )
+        self.messages.append(msg)
+
+
 class TestUserNotificationUnit(unittest.TestCase):
 
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
         # Set up a mock mailhost
         self.portal._original_MailHost = self.portal.MailHost
-        self.portal.MailHost = mailhost = MockMailHost('MailHost')
+        self.portal.MailHost = mailhost = MockMailHost("MailHost")
         sm = getSiteManager(context=self.portal)
         sm.unregisterUtility(provided=IMailHost)
         sm.registerUtility(mailhost, provided=IMailHost)
         # We need to fake a valid mail setup
         registry = getUtility(IRegistry)
-        mail_settings = registry.forInterface(IMailSchema, prefix='plone')
-        mail_settings.email_from_address = 'portal@plone.test'
+        mail_settings = registry.forInterface(IMailSchema, prefix="plone")
+        mail_settings.email_from_address = "portal@plone.test"
         self.mailhost = self.portal.MailHost
         # Enable user notification setting
         registry = queryUtility(IRegistry)
-        registry['plone.app.discussion.interfaces.IDiscussionSettings' +
-                 '.user_notification_enabled'] = True
-        # Archetypes content types store data as utf-8 encoded strings
-        # The missing u in front of a string is therefor not missing
-        self.portal.doc1.title = 'Kölle Alaaf'  # What is 'Fasching'?
+        registry[
+            "plone.app.discussion.interfaces.IDiscussionSettings"
+            + ".user_notification_enabled"
+        ] = True
+        self.portal.doc1.title = "Kölle Alaaf"  # What is 'Fasching'?
         self.conversation = IConversation(self.portal.doc1)
 
     def beforeTearDown(self):
         self.portal.MailHost = self.portal._original_MailHost
         sm = getSiteManager(context=self.portal)
         sm.unregisterUtility(provided=IMailHost)
-        sm.registerUtility(aq_base(self.portal._original_MailHost),
-                           provided=IMailHost)
+        sm.registerUtility(aq_base(self.portal._original_MailHost), provided=IMailHost)
 
     def test_notify_user(self):
         # Add a comment with user notification enabled. Add another comment
         # and make sure an email is send to the user of the first comment.
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         comment.user_notification = True
-        comment.author_email = 'john@plone.test'
+        comment.author_email = "john@plone.test"
         self.conversation.addComment(comment)
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
 
         comment_id = self.conversation.addComment(comment)
 
@@ -67,52 +103,46 @@ class TestUserNotificationUnit(unittest.TestCase):
         self.assertTrue(self.mailhost.messages[0])
         msg = self.mailhost.messages[0]
         msg = msg.decode("utf-8")
-        self.assertIn('To: john@plone.test', msg)
-        self.assertIn('From: portal@plone.test', msg)
+        self.assertIn("To: john@plone.test", msg)
+        self.assertIn("From: portal@plone.test", msg)
         # We expect the headers to be properly header encoded (7-bit):
-        self.assertIn(
-            'Subject: =?utf-8?q?A_comment_has_been_posted=2E?=',
-            msg)
+        self.assertIn("Subject: =?utf-8?q?A_comment_has_been_posted=2E?=", msg)
         # The output should be encoded in a reasonable manner
         # (in this case quoted-printable).
         # Depending on which Python version and which Products.MailHost version,
         # you may get lines separated by '\n' or '\r\n' in here.
-        msg = msg.replace('\r\n', '\n')
-        self.assertIn(
-            'A comment on "K=C3=B6lle Alaaf" has been posted here:',
-            msg)
-        self.assertIn(
-            'http://nohost/plone/d=\noc1/view#{0}'.format(comment_id),
-            msg)
-        self.assertIn('Comment text', msg)
-        self.assertNotIn('Approve comment', msg)
-        self.assertNotIn('Delete comment', msg)
+        msg = msg.replace("\r\n", "\n")
+        self.assertIn('A comment on "K=C3=B6lle Alaaf" has been posted here:', msg)
+        self.assertIn(f"http://nohost/plone/d=\noc1/view#{comment_id}", msg)
+        self.assertIn("Comment text", msg)
+        self.assertNotIn("Approve comment", msg)
+        self.assertNotIn("Delete comment", msg)
 
     def test_do_not_notify_user_when_notification_is_disabled(self):
         registry = queryUtility(IRegistry)
         registry[
-            'plone.app.discussion.interfaces.IDiscussionSettings.' +
-            'user_notification_enabled'
+            "plone.app.discussion.interfaces.IDiscussionSettings."
+            + "user_notification_enabled"
         ] = False
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         comment.user_notification = True
-        comment.author_email = 'john@plone.test'
+        comment.author_email = "john@plone.test"
         self.conversation.addComment(comment)
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
 
         self.conversation.addComment(comment)
 
         self.assertEqual(len(self.mailhost.messages), 0)
 
     def test_do_not_notify_user_when_email_address_is_given(self):
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         comment.user_notification = True
         self.conversation.addComment(comment)
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
 
         self.conversation.addComment(comment)
 
@@ -122,15 +152,15 @@ class TestUserNotificationUnit(unittest.TestCase):
         # Set sender mail address to none and make sure no email is send to
         # the moderator.
         registry = getUtility(IRegistry)
-        mail_settings = registry.forInterface(IMailSchema, prefix='plone')
+        mail_settings = registry.forInterface(IMailSchema, prefix="plone")
         mail_settings.email_from_address = None
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         comment.user_notification = True
-        comment.author_email = 'john@plone.test'
+        comment.author_email = "john@plone.test"
         self.conversation.addComment(comment)
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
 
         self.conversation.addComment(comment)
         self.assertEqual(len(self.mailhost.messages), 0)
@@ -139,15 +169,15 @@ class TestUserNotificationUnit(unittest.TestCase):
         # When a user has added two comments in a conversation and has
         # both times requested email notification, do not send him two
         # emails when another comment has been added.
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         comment.user_notification = True
-        comment.author_email = 'john@plone.test'
+        comment.author_email = "john@plone.test"
         self.conversation.addComment(comment)
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         comment.user_notification = True
-        comment.author_email = 'john@plone.test'
+        comment.author_email = "john@plone.test"
 
         self.conversation.addComment(comment)
 
@@ -163,48 +193,45 @@ class TestModeratorNotificationUnit(unittest.TestCase):
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
         # Set up a mock mailhost
         self.portal._original_MailHost = self.portal.MailHost
-        self.portal.MailHost = mailhost = MockMailHost('MailHost')
+        self.portal.MailHost = mailhost = MockMailHost("MailHost")
         sm = getSiteManager(context=self.portal)
         sm.unregisterUtility(provided=IMailHost)
         sm.registerUtility(mailhost, provided=IMailHost)
         # We need to fake a valid mail setup
         registry = getUtility(IRegistry)
-        mail_settings = registry.forInterface(IMailSchema, prefix='plone')
-        mail_settings.email_from_address = 'portal@plone.test'
+        mail_settings = registry.forInterface(IMailSchema, prefix="plone")
+        mail_settings.email_from_address = "portal@plone.test"
         self.mailhost = self.portal.MailHost
         # Enable comment moderation
-        self.portal.portal_types['Document'].allow_discussion = True
+        self.portal.portal_types["Document"].allow_discussion = True
         self.portal.portal_workflow.setChainForPortalTypes(
-            ('Discussion Item',),
-            ('comment_review_workflow',),
+            ("Discussion Item",),
+            ("comment_review_workflow",),
         )
         # Enable moderator notification setting
         registry = queryUtility(IRegistry)
         registry[
-            'plone.app.discussion.interfaces.IDiscussionSettings.' +
-            'moderator_notification_enabled'
+            "plone.app.discussion.interfaces.IDiscussionSettings."
+            + "moderator_notification_enabled"
         ] = True
-        # Archetypes content types store data as utf-8 encoded strings
-        # The missing u in front of a string is therefor not missing
-        self.portal.doc1.title = 'Kölle Alaaf'  # What is 'Fasching'?
+        self.portal.doc1.title = "Kölle Alaaf"  # What is 'Fasching'?
         self.conversation = IConversation(self.portal.doc1)
 
     def beforeTearDown(self):
         self.portal.MailHost = self.portal._original_MailHost
         sm = getSiteManager(context=self.portal)
         sm.unregisterUtility(provided=IMailHost)
-        sm.registerUtility(aq_base(self.portal._original_MailHost),
-                           provided=IMailHost)
+        sm.registerUtility(aq_base(self.portal._original_MailHost), provided=IMailHost)
 
     def test_notify_moderator(self):
         """Add a comment and make sure an email is send to the moderator."""
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
-        comment.author_email = 'john@plone.test'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
+        comment.author_email = "john@plone.test"
 
         comment_id = self.conversation.addComment(comment)
 
@@ -212,54 +239,41 @@ class TestModeratorNotificationUnit(unittest.TestCase):
         self.assertTrue(self.mailhost.messages[0])
         msg = self.mailhost.messages[0]
         msg = msg.decode("utf-8")
-        self.assertTrue('To: portal@plone.test' in msg)
-        self.assertTrue('From: portal@plone.test' in msg)
+        self.assertTrue("To: portal@plone.test" in msg)
+        self.assertTrue("From: portal@plone.test" in msg)
         # We expect the headers to be properly header encoded (7-bit):
-        self.assertTrue(
-            'Subject: =?utf-8?q?A_comment_has_been_posted=2E?='
-            in msg)
+        self.assertTrue("Subject: =?utf-8?q?A_comment_has_been_posted=2E?=" in msg)
         # The output should be encoded in a reasonable manner
         # (in this case quoted-printable):
-        self.assertTrue(
-            'A comment on "K=C3=B6lle Alaaf" has been posted'
-            in msg
-        )
-        self.assertIn(
-            'http://nohost/plone/doc1/view#{0}'.format(comment_id),
-            msg
-        )
-        self.assertIn(
-            comment.author_email,
-            msg
-        )
-        self.assertIn(
-            comment.text,
-            msg
-        )
+        self.assertTrue('A comment on "K=C3=B6lle Alaaf" has been posted' in msg)
+        self.assertIn(f"http://nohost/plone/doc1/view#{comment_id}", msg)
+        self.assertIn(comment.author_email, msg)
+        self.assertIn(comment.text, msg)
 
     def test_notify_moderator_specific_address(self):
         # A moderator email address can be specified in the control panel.
         registry = queryUtility(IRegistry)
-        registry['plone.app.discussion.interfaces.IDiscussionSettings' +
-                 '.moderator_email'] = 'test@example.com'
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        registry[
+            "plone.app.discussion.interfaces.IDiscussionSettings" + ".moderator_email"
+        ] = "test@example.com"
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
 
         self.conversation.addComment(comment)
 
         self.assertEqual(len(self.mailhost.messages), 1)
         msg = self.mailhost.messages[0]
         msg = msg.decode("utf-8")
-        self.assertTrue('To: test@example.com' in msg)
+        self.assertTrue("To: test@example.com" in msg)
 
     def test_do_not_notify_moderator_when_no_sender_is_available(self):
         # Set sender mail address to nonw and make sure no email is send to the
         # moderator.
         registry = getUtility(IRegistry)
-        mail_settings = registry.forInterface(IMailSchema, prefix='plone')
+        mail_settings = registry.forInterface(IMailSchema, prefix="plone")
         mail_settings.email_from_address = None
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
 
         self.conversation.addComment(comment)
 
@@ -269,10 +283,12 @@ class TestModeratorNotificationUnit(unittest.TestCase):
         # Disable moderator notification setting and make sure no email is send
         # to the moderator.
         registry = queryUtility(IRegistry)
-        registry['plone.app.discussion.interfaces.IDiscussionSettings.' +
-                 'moderator_notification_enabled'] = False
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        registry[
+            "plone.app.discussion.interfaces.IDiscussionSettings."
+            + "moderator_notification_enabled"
+        ] = False
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
 
         self.conversation.addComment(comment)
 
diff --git a/plone/app/discussion/tests/test_robot.py b/plone/app/discussion/tests/test_robot.py
index 202b43b..c626689 100644
--- a/plone/app/discussion/tests/test_robot.py
+++ b/plone/app/discussion/tests/test_robot.py
@@ -1,5 +1,4 @@
-# -*- coding: utf-8 -*-
-from plone.app.discussion.testing import PLONE_APP_DISCUSSION_ROBOT_TESTING
+from ..testing import PLONE_APP_DISCUSSION_ROBOT_TESTING
 from plone.app.testing import ROBOT_TEST_LEVEL
 from plone.testing import layered
 
@@ -11,19 +10,21 @@ import unittest
 def test_suite():
     suite = unittest.TestSuite()
     current_dir = os.path.abspath(os.path.dirname(__file__))
-    robot_dir = os.path.join(current_dir, 'robot')
+    robot_dir = os.path.join(current_dir, "robot")
     robot_tests = [
-        os.path.join('robot', doc) for doc in
-        os.listdir(robot_dir) if doc.endswith('.robot') and
-        doc.startswith('test_')
+        os.path.join("robot", doc)
+        for doc in os.listdir(robot_dir)
+        if doc.endswith(".robot") and doc.startswith("test_")
     ]
     for robot_test in robot_tests:
         robottestsuite = robotsuite.RobotTestSuite(robot_test)
         robottestsuite.level = ROBOT_TEST_LEVEL
-        suite.addTests([
-            layered(
-                robottestsuite,
-                layer=PLONE_APP_DISCUSSION_ROBOT_TESTING,
-            ),
-        ])
+        suite.addTests(
+            [
+                layered(
+                    robottestsuite,
+                    layer=PLONE_APP_DISCUSSION_ROBOT_TESTING,
+                ),
+            ]
+        )
     return suite
diff --git a/plone/app/discussion/tests/test_workflow.py b/plone/app/discussion/tests/test_workflow.py
index 9f959fc..ece7d8a 100644
--- a/plone/app/discussion/tests/test_workflow.py
+++ b/plone/app/discussion/tests/test_workflow.py
@@ -1,10 +1,9 @@
-# -*- coding: utf-8 -*-
 """Test plone.app.discussion workflow and permissions.
 """
+from ..interfaces import IConversation
+from ..interfaces import IDiscussionLayer
+from ..testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 from AccessControl import Unauthorized
-from plone.app.discussion.interfaces import IConversation
-from plone.app.discussion.interfaces import IDiscussionLayer
-from plone.app.discussion.testing import PLONE_APP_DISCUSSION_INTEGRATION_TESTING  # noqa
 from plone.app.testing import login
 from plone.app.testing import logout
 from plone.app.testing import setRoles
@@ -19,48 +18,51 @@ import unittest
 
 
 class WorkflowSetupTest(unittest.TestCase):
-    """Make sure the workflows are set up properly.
-    """
+    """Make sure the workflows are set up properly."""
 
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
-        self.portal.invokeFactory('Folder', 'test-folder')
-        self.folder = self.portal['test-folder']
-        self.portal.portal_types['Document'].allow_discussion = True
-        self.folder.invokeFactory('Document', 'doc1')
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
+        self.portal.invokeFactory("Folder", "test-folder")
+        self.folder = self.portal["test-folder"]
+        self.portal.portal_types["Document"].allow_discussion = True
+        self.folder.invokeFactory("Document", "doc1")
         self.doc = self.folder.doc1
 
     def test_workflows_installed(self):
-        """Make sure both comment workflows have been installed properly.
-        """
-        self.assertTrue('comment_one_state_workflow' in
-                        self.portal.portal_workflow.objectIds())
-        self.assertTrue('comment_review_workflow' in
-                        self.portal.portal_workflow.objectIds())
+        """Make sure both comment workflows have been installed properly."""
+        self.assertTrue(
+            "comment_one_state_workflow" in self.portal.portal_workflow.objectIds()
+        )
+        self.assertTrue(
+            "comment_review_workflow" in self.portal.portal_workflow.objectIds()
+        )
 
     def test_default_workflow(self):
-        """Make sure one_state_workflow is the default workflow.
-        """
+        """Make sure one_state_workflow is the default workflow."""
         self.assertEqual(
-            ('comment_one_state_workflow',),
+            ("comment_one_state_workflow",),
             self.portal.portal_workflow.getChainForPortalType(
-                'Discussion Item',
+                "Discussion Item",
             ),
         )
 
     def test_review_comments_permission(self):
         # 'Review comments' in self.portal.permissionsOfRole('Admin')
 
-        setRoles(self.portal, TEST_USER_ID, ['Reviewer'])
-        self.assertTrue(self.portal.portal_membership.checkPermission(
-                        'Review comments', self.folder), self.folder)
-        setRoles(self.portal, TEST_USER_ID, ['Member'])
+        setRoles(self.portal, TEST_USER_ID, ["Reviewer"])
+        self.assertTrue(
+            self.portal.portal_membership.checkPermission(
+                "Review comments", self.folder
+            ),
+            self.folder,
+        )
+        setRoles(self.portal, TEST_USER_ID, ["Member"])
         self.assertFalse(
             self.portal.portal_membership.checkPermission(
-                'Review comments',
+                "Review comments",
                 self.folder,
             ),
             self.folder,
@@ -71,31 +73,30 @@ class WorkflowSetupTest(unittest.TestCase):
 
 
 class PermissionsSetupTest(unittest.TestCase):
-    """Make sure the permissions are set up properly.
-    """
+    """Make sure the permissions are set up properly."""
 
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
         mtool = self.portal.portal_membership
         self.checkPermission = mtool.checkPermission
 
     def test_reply_to_item_permission_assigned(self):
         """Make sure the 'Reply to item' permission is properly assigned.
-           By default this permission is assigned to 'Member' and 'Manager'.
-           plone.app.discussion assigns this permission to 'Authenticated' as
-           well to emulate the behavior of the old commenting system.
+        By default this permission is assigned to 'Member' and 'Manager'.
+        plone.app.discussion assigns this permission to 'Authenticated' as
+        well to emulate the behavior of the old commenting system.
         """
-        ReplyToItemPerm = 'Reply to item'
+        ReplyToItemPerm = "Reply to item"
         # should be allowed as Member
         self.assertTrue(self.checkPermission(ReplyToItemPerm, self.portal))
         # should be allowed as Authenticated
-        setRoles(self.portal, TEST_USER_ID, ['Authenticated'])
+        setRoles(self.portal, TEST_USER_ID, ["Authenticated"])
         self.assertTrue(self.checkPermission(ReplyToItemPerm, self.portal))
         # should be allowed as Manager
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
         self.assertTrue(self.checkPermission(ReplyToItemPerm, self.portal))
         # should not be allowed as anonymous
         logout()
@@ -103,70 +104,66 @@ class PermissionsSetupTest(unittest.TestCase):
 
 
 class CommentOneStateWorkflowTest(unittest.TestCase):
-    """Test the comment_one_state_workflow that ships with plone.app.discussion.
-    """
+    """Test the comment_one_state_workflow that ships with plone.app.discussion."""
 
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
-        self.portal.invokeFactory('Folder', 'test-folder')
-        self.folder = self.portal['test-folder']
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
+        self.portal.invokeFactory("Folder", "test-folder")
+        self.folder = self.portal["test-folder"]
         self.catalog = self.portal.portal_catalog
         self.workflow = self.portal.portal_workflow
-        self.folder.invokeFactory('Document', 'doc1')
+        self.folder.invokeFactory("Document", "doc1")
         self.doc = self.folder.doc1
 
         # Add a comment
         conversation = IConversation(self.folder.doc1)
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         cid = conversation.addComment(comment)
 
         self.comment = self.folder.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(cid),
+            f"++conversation++default/{cid}",
         )
 
-        self.portal.acl_users._doAddUser('member', 'secret', ['Member'], [])
-        self.portal.acl_users._doAddUser(
-            'reviewer', 'secret', ['Reviewer'], [])
-        self.portal.acl_users._doAddUser('manager', 'secret', ['Manager'], [])
-        self.portal.acl_users._doAddUser('editor', ' secret', ['Editor'], [])
-        self.portal.acl_users._doAddUser('reader', 'secret', ['Reader'], [])
+        self.portal.acl_users._doAddUser("member", "secret", ["Member"], [])
+        self.portal.acl_users._doAddUser("reviewer", "secret", ["Reviewer"], [])
+        self.portal.acl_users._doAddUser("manager", "secret", ["Manager"], [])
+        self.portal.acl_users._doAddUser("editor", " secret", ["Editor"], [])
+        self.portal.acl_users._doAddUser("reader", "secret", ["Reader"], [])
 
     def test_initial_workflow_state(self):
-        """Make sure the initial workflow state of a comment is 'private'.
-        """
+        """Make sure the initial workflow state of a comment is 'private'."""
         self.assertEqual(
-            self.workflow.getInfoFor(self.doc, 'review_state'),
-            'private',
+            self.workflow.getInfoFor(self.doc, "review_state"),
+            "private",
         )
 
     def test_view_comments(self):
-        """Make sure published comments can be viewed by everyone.
-        """
+        """Make sure published comments can be viewed by everyone."""
         # Owner is allowed
         # self.login(default_user)
         # self.assertTrue(checkPerm(View, self.doc))
         # Member is allowed
         login(self.portal, TEST_USER_NAME)
         workflow = self.portal.portal_workflow
-        workflow.doActionFor(self.doc, 'publish')
+        workflow.doActionFor(self.doc, "publish")
 
-        login(self.portal, 'member')
+        login(self.portal, "member")
         self.assertTrue(checkPerm(View, self.comment))
         # Reviewer is allowed
-        login(self.portal, 'reviewer')
+        login(self.portal, "reviewer")
         self.assertTrue(checkPerm(View, self.comment))
         # Anonymous is allowed
         logout()
         self.assertTrue(checkPerm(View, self.comment))
         # Editor is allowed
-        login(self.portal, 'editor')
+        login(self.portal, "editor")
         self.assertTrue(checkPerm(View, self.comment))
         # Reader is allowed
-        login(self.portal, 'reader')
+        login(self.portal, "reader")
         self.assertTrue(checkPerm(View, self.comment))
 
     def test_comment_on_private_content_not_visible_to_world(self):
@@ -175,8 +172,9 @@ class CommentOneStateWorkflowTest(unittest.TestCase):
 
     def test_migration(self):
         from plone.app.discussion.upgrades import upgrade_comment_workflows
+
         # Fake permission according to earlier one_comment_workflow.
-        self.comment._View_Permission = ('Anonymous',)
+        self.comment._View_Permission = ("Anonymous",)
         # Anonymous can see the comment.
         logout()
         self.assertTrue(checkPerm(View, self.comment))
@@ -185,8 +183,8 @@ class CommentOneStateWorkflowTest(unittest.TestCase):
         upgrade_comment_workflows(self.portal.portal_setup)
         # The workflow chain is still what we want.
         self.assertEqual(
-            self.portal.portal_workflow.getChainFor('Discussion Item'),
-            ('comment_one_state_workflow',),
+            self.portal.portal_workflow.getChainFor("Discussion Item"),
+            ("comment_one_state_workflow",),
         )
         # A Manager can still see the comment.
         self.assertTrue(checkPerm(View, self.comment))
@@ -196,112 +194,112 @@ class CommentOneStateWorkflowTest(unittest.TestCase):
 
 
 class CommentReviewWorkflowTest(unittest.TestCase):
-    """Test the comment_review_workflow that ships with plone.app.discussion.
-    """
+    """Test the comment_review_workflow that ships with plone.app.discussion."""
 
     layer = PLONE_APP_DISCUSSION_INTEGRATION_TESTING
 
     def setUp(self):
-        self.portal = self.layer['portal']
-        setRoles(self.portal, TEST_USER_ID, ['Manager'])
-        self.portal.invokeFactory('Folder', 'test-folder')
-        self.folder = self.portal['test-folder']
+        self.portal = self.layer["portal"]
+        setRoles(self.portal, TEST_USER_ID, ["Manager"])
+        self.portal.invokeFactory("Folder", "test-folder")
+        self.folder = self.portal["test-folder"]
 
         # Allow discussion on the Document content type
-        self.portal.portal_types['Document'].allow_discussion = True
+        self.portal.portal_types["Document"].allow_discussion = True
         # Set workflow for Discussion item to review workflow
         self.portal.portal_workflow.setChainForPortalTypes(
-            ('Discussion Item',),
-            ('comment_review_workflow',),
+            ("Discussion Item",),
+            ("comment_review_workflow",),
         )
 
         # Create a conversation for this Document
         conversation = IConversation(self.portal.doc1)
 
         # Add a comment.
-        comment = createObject('plone.Comment')
-        comment.text = 'Comment text'
+        comment = createObject("plone.Comment")
+        comment.text = "Comment text"
         comment_id = conversation.addComment(comment)
         comment = self.portal.doc1.restrictedTraverse(
-            '++conversation++default/{0}'.format(comment_id),
+            f"++conversation++default/{comment_id}",
         )
 
         self.conversation = conversation
         self.comment_id = comment_id
         self.comment = comment
 
-        setRoles(self.portal, TEST_USER_ID, ['Reviewer'])
+        setRoles(self.portal, TEST_USER_ID, ["Reviewer"])
         alsoProvides(self.portal.REQUEST, IDiscussionLayer)
 
     def test_delete(self):
-        self.portal.REQUEST.form['comment_id'] = self.comment_id
-        view = self.comment.restrictedTraverse('@@moderate-delete-comment')
+        self.portal.REQUEST.form["comment_id"] = self.comment_id
+        view = self.comment.restrictedTraverse("@@moderate-delete-comment")
         view()
         self.assertFalse(self.comment_id in self.conversation.objectIds())
 
     def test_delete_as_anonymous(self):
         # Make sure that anonymous users can not delete comments
         logout()
-        self.portal.REQUEST.form['comment_id'] = self.comment_id
+        self.portal.REQUEST.form["comment_id"] = self.comment_id
         self.assertRaises(
             Unauthorized,
             self.comment.restrictedTraverse,
-            '@@moderate-delete-comment',
+            "@@moderate-delete-comment",
         )
         self.assertTrue(self.comment_id in self.conversation.objectIds())
 
     def test_delete_as_user(self):
         # Make sure that members can not delete comments
         logout()
-        setRoles(self.portal, TEST_USER_ID, ['Member'])
-        self.portal.REQUEST.form['comment_id'] = self.comment_id
+        setRoles(self.portal, TEST_USER_ID, ["Member"])
+        self.portal.REQUEST.form["comment_id"] = self.comment_id
         self.assertRaises(
             Unauthorized,
             self.comment.restrictedTraverse,
-            '@@moderate-delete-comment',
+            "@@moderate-delete-comment",
         )
         self.assertTrue(self.comment_id in self.conversation.objectIds())
 
     def test_publish(self):
-        self.portal.REQUEST.form['comment_id'] = self.comment_id
-        self.portal.REQUEST.form['workflow_action'] = 'publish'
+        self.portal.REQUEST.form["comment_id"] = self.comment_id
+        self.portal.REQUEST.form["workflow_action"] = "publish"
         self.assertEqual(
-            'pending',
+            "pending",
             self.portal.portal_workflow.getInfoFor(
                 self.comment,
-                'review_state',
+                "review_state",
             ),
         )
-        view = self.comment.restrictedTraverse('@@transmit-comment')
+        view = self.comment.restrictedTraverse("@@transmit-comment")
         view()
         self.assertEqual(
-            'published',
+            "published",
             self.portal.portal_workflow.getInfoFor(
                 self.comment,
-                'review_state',
+                "review_state",
             ),
         )
 
     def test_publish_as_anonymous(self):
         logout()
-        self.portal.REQUEST.form['comment_id'] = self.comment_id
-        self.portal.REQUEST.form['workflow_action'] = 'publish'
+        self.portal.REQUEST.form["comment_id"] = self.comment_id
+        self.portal.REQUEST.form["workflow_action"] = "publish"
         self.assertEqual(
-            'pending', self.portal.portal_workflow.getInfoFor(
+            "pending",
+            self.portal.portal_workflow.getInfoFor(
                 self.comment,
-                'review_state',
+                "review_state",
             ),
         )
         self.assertRaises(
             Unauthorized,
             self.comment.restrictedTraverse,
-            '@@transmit-comment',
+            "@@transmit-comment",
         )
         self.assertEqual(
-            'pending',
+            "pending",
             self.portal.portal_workflow.getInfoFor(
                 self.comment,
-                'review_state',
+                "review_state",
             ),
         )
 
@@ -312,15 +310,16 @@ class CommentReviewWorkflowTest(unittest.TestCase):
         # publish comment and check again
         login(self.portal, TEST_USER_NAME)
         workflow = self.portal.portal_workflow
-        workflow.doActionFor(self.comment, 'publish')
+        workflow.doActionFor(self.comment, "publish")
 
         logout()
         self.assertFalse(checkPerm(View, self.comment))
 
     def test_migration(self):
         from plone.app.discussion.upgrades import upgrade_comment_workflows
+
         # Fake permission according to earlier comment_review_workflow.
-        self.comment._View_Permission = ('Anonymous',)
+        self.comment._View_Permission = ("Anonymous",)
         # Anonymous can see the comment.
         logout()
         self.assertTrue(checkPerm(View, self.comment))
@@ -329,8 +328,9 @@ class CommentReviewWorkflowTest(unittest.TestCase):
         upgrade_comment_workflows(self.portal.portal_setup)
         # The workflow chain is still what we want.
         self.assertEqual(
-            self.portal.portal_workflow.getChainFor('Discussion Item'),
-            ('comment_review_workflow',))
+            self.portal.portal_workflow.getChainFor("Discussion Item"),
+            ("comment_review_workflow",),
+        )
         # A Manager can still see the comment.
         self.assertTrue(checkPerm(View, self.comment))
         # Anonymous cannot see the comment.
diff --git a/plone/app/discussion/tool.py b/plone/app/discussion/tool.py
index a10ae3c..50f9361 100644
--- a/plone/app/discussion/tool.py
+++ b/plone/app/discussion/tool.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 """The portal_discussion tool, usually accessed via
 queryUtility(ICommentingTool). The default implementation delegates to the
 standard portal_catalog for indexing comments.
@@ -17,62 +16,60 @@ from zope.component import queryUtility
 @interface.implementer(ICommentingTool)
 class CommentingTool(UniqueObject, SimpleItem):
 
-    meta_type = 'plone.app.discussion tool'
-    id = 'portal_discussion'
+    meta_type = "plone.app.discussion tool"
+    id = "portal_discussion"
 
     def reindexObject(self, object):
         # Reindex in catalog.
-        catalog = getToolByName(self, 'portal_catalog')
+        catalog = getToolByName(self, "portal_catalog")
         return catalog.reindexObject(object)
 
     indexObject = reindexObject
 
     def unindexObject(self, object):
         # Remove from catalog.
-        catalog = getToolByName(self, 'portal_catalog')
+        catalog = getToolByName(self, "portal_catalog")
         return catalog.unindexObject(object)
 
     def uniqueValuesFor(self, name):
         # return unique values for FieldIndex name
-        catalog = getToolByName(self, 'portal_catalog')
+        catalog = getToolByName(self, "portal_catalog")
         return catalog.uniqueValuesFor(name)
 
     def searchResults(self, REQUEST=None, **kw):
         # Calls ZCatalog.searchResults with extra arguments that
         # limit the results to what the user is allowed to see.
-        catalog = getToolByName(self, 'portal_catalog')
+        catalog = getToolByName(self, "portal_catalog")
         object_provides = [IComment.__identifier__]
 
-        if 'object_provides' in kw:
-            kw_provides = kw['object_provides']
+        if "object_provides" in kw:
+            kw_provides = kw["object_provides"]
             if isinstance(str, kw_provides):
                 object_provides.append(kw_provides)
             else:
                 object_provides.extend(kw_provides)
 
-        if REQUEST is not None and 'object_provides' in REQUEST.form:
-            rq_provides = REQUEST.form['object_provides']
-            del REQUEST.form['object_provides']
+        if REQUEST is not None and "object_provides" in REQUEST.form:
+            rq_provides = REQUEST.form["object_provides"]
+            del REQUEST.form["object_provides"]
             if isinstance(str, rq_provides):
                 object_provides.append(rq_provides)
             else:
                 object_provides.extend(rq_provides)
 
-        kw['object_provides'] = object_provides
+        kw["object_provides"] = object_provides
         return catalog.searchResults(REQUEST, **kw)
 
 
 def index_object(obj, event):
-    """Index the object when added to the conversation
-    """
+    """Index the object when added to the conversation"""
     tool = queryUtility(ICommentingTool)
     if tool is not None:
         tool.indexObject(obj)
 
 
 def unindex_object(obj, event):
-    """Unindex the object when removed
-    """
+    """Unindex the object when removed"""
     tool = queryUtility(ICommentingTool)
     if tool is not None:
         tool.unindexObject(obj)
diff --git a/plone/app/discussion/upgrades.py b/plone/app/discussion/upgrades.py
index 784184e..40cdc8f 100644
--- a/plone/app/discussion/upgrades.py
+++ b/plone/app/discussion/upgrades.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 from plone.app.discussion.interfaces import IDiscussionSettings
 from plone.registry.interfaces import IRegistry
 from Products.CMFCore.utils import getToolByName
@@ -7,8 +6,8 @@ from zope.component import getUtility
 import logging
 
 
-default_profile = 'profile-plone.app.discussion:default'
-logger = logging.getLogger('plone.app.discussion')
+default_profile = "profile-plone.app.discussion:default"
+logger = logging.getLogger("plone.app.discussion")
 
 
 def update_registry(context):
@@ -17,7 +16,7 @@ def update_registry(context):
 
 
 def update_rolemap(context):
-    context.runImportStepFromProfile(default_profile, 'rolemap')
+    context.runImportStepFromProfile(default_profile, "rolemap")
 
 
 def upgrade_comment_workflows_retain_current_workflow(context):
@@ -25,16 +24,16 @@ def upgrade_comment_workflows_retain_current_workflow(context):
     # import step will change it to comment_one_state_workflow.  This is good.
     # If it was anything else, we should restore this.  So get the original
     # chain.
-    portal_type = 'Discussion Item'
-    wf_tool = getToolByName(context, 'portal_workflow')
+    portal_type = "Discussion Item"
+    wf_tool = getToolByName(context, "portal_workflow")
     orig_chain = list(wf_tool.getChainFor(portal_type))
 
     # Run the workflow step.  This sets the chain to
     # comment_one_state_workflow.
-    context.runImportStepFromProfile(default_profile, 'workflow')
+    context.runImportStepFromProfile(default_profile, "workflow")
 
     # Restore original workflow chain if needed.
-    old_workflow = 'one_state_workflow'
+    old_workflow = "one_state_workflow"
     if old_workflow not in orig_chain:
         # Restore the chain.  Probably comment_review_workflow.
         wf_tool.setChainForPortalTypes([portal_type], orig_chain)
@@ -43,7 +42,7 @@ def upgrade_comment_workflows_retain_current_workflow(context):
         if old_workflow in orig_chain:
             # Replace with new one.
             idx = orig_chain.index(old_workflow)
-            orig_chain[idx] = 'comment_one_state_workflow'
+            orig_chain[idx] = "comment_one_state_workflow"
         # Restore the chain.
         wf_tool.setChainForPortalTypes([portal_type], orig_chain)
 
@@ -51,9 +50,9 @@ def upgrade_comment_workflows_retain_current_workflow(context):
 def upgrade_comment_workflows_apply_rolemapping(context):
     # Now go over the comments, update their role mappings, and reindex the
     # allowedRolesAndUsers index.
-    portal_type = 'Discussion Item'
-    catalog = getToolByName(context, 'portal_catalog')
-    wf_tool = getToolByName(context, 'portal_workflow')
+    portal_type = "Discussion Item"
+    catalog = getToolByName(context, "portal_catalog")
+    wf_tool = getToolByName(context, "portal_workflow")
     new_chain = list(wf_tool.getChainFor(portal_type))
     workflows = [wf_tool.getWorkflowById(wf_id) for wf_id in new_chain]
     for brain in catalog.unrestrictedSearchResults(portal_type=portal_type):
@@ -63,7 +62,7 @@ def upgrade_comment_workflows_apply_rolemapping(context):
                 wf.updateRoleMappingsFor(comment)
             comment.reindexObjectSecurity()
         except (AttributeError, KeyError):
-            logger.info('Could not reindex comment {0}'.format(brain.getURL()))
+            logger.info(f"Could not reindex comment {brain.getURL()}")
 
 
 def upgrade_comment_workflows(context):
@@ -72,7 +71,7 @@ def upgrade_comment_workflows(context):
 
 
 def add_js_to_plone_legacy(context):
-    context.runImportStepFromProfile(default_profile, 'plone.app.registry')
+    context.runImportStepFromProfile(default_profile, "plone.app.registry")
 
 
 def extend_review_workflow(context):
diff --git a/plone/app/discussion/vocabularies.py b/plone/app/discussion/vocabularies.py
index b158866..290448d 100644
--- a/plone/app/discussion/vocabularies.py
+++ b/plone/app/discussion/vocabularies.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 from plone.app.discussion.interfaces import _
 from zope.schema.vocabulary import SimpleTerm
 from zope.schema.vocabulary import SimpleVocabulary
@@ -7,6 +6,7 @@ from zope.schema.vocabulary import SimpleVocabulary
 HAS_CAPTCHA = False
 try:
     import plone.formwidget.captcha  # noqa
+
     HAS_CAPTCHA = True  # pragma: no cover
 except ImportError:
     pass
@@ -14,6 +14,7 @@ except ImportError:
 HAS_RECAPTCHA = False
 try:
     import plone.formwidget.recaptcha  # noqa
+
     HAS_RECAPTCHA = True  # pragma: no cover
 except ImportError:
     pass
@@ -21,6 +22,7 @@ except ImportError:
 HAS_AKISMET = False
 try:
     import collective.akismet  # noqa
+
     HAS_AKISMET = True  # pragma: no cover
 except ImportError:
     pass
@@ -28,73 +30,48 @@ except ImportError:
 HAS_NOROBOTS = False
 try:
     import collective.z3cform.norobots  # noqa
+
     HAS_NOROBOTS = True  # pragma: no cover
 except ImportError:
     pass
 
 
 def captcha_vocabulary(context):
-    """Vocabulary with all available captcha implementations.
-    """
+    """Vocabulary with all available captcha implementations."""
     terms = []
-    terms.append(
-        SimpleTerm(
-            value='disabled',
-            token='disabled',
-            title=_(u'Disabled')))
+    terms.append(SimpleTerm(value="disabled", token="disabled", title=_("Disabled")))
 
     if HAS_CAPTCHA:  # pragma: no cover
-        terms.append(
-            SimpleTerm(
-                value='captcha',
-                token='captcha',
-                title='Captcha'))
+        terms.append(SimpleTerm(value="captcha", token="captcha", title="Captcha"))
 
     if HAS_RECAPTCHA:  # pragma: no cover
         terms.append(
-            SimpleTerm(
-                value='recaptcha',
-                token='recaptcha',
-                title='ReCaptcha'))
+            SimpleTerm(value="recaptcha", token="recaptcha", title="ReCaptcha")
+        )
 
     if HAS_AKISMET:  # pragma: no cover
-        terms.append(
-            SimpleTerm(
-                value='akismet',
-                token='akismet',
-                title='Akismet'))
+        terms.append(SimpleTerm(value="akismet", token="akismet", title="Akismet"))
 
     if HAS_NOROBOTS:  # pragma: no cover
-        terms.append(
-            SimpleTerm(
-                value='norobots',
-                token='norobots',
-                title='Norobots'))
+        terms.append(SimpleTerm(value="norobots", token="norobots", title="Norobots"))
     return SimpleVocabulary(terms)
 
 
 def text_transform_vocabulary(context):
-    """Vocabulary with all available portal_transform transformations.
-    """
+    """Vocabulary with all available portal_transform transformations."""
     terms = []
+    terms.append(SimpleTerm(value="text/plain", token="text/plain", title="Plain text"))
+    terms.append(SimpleTerm(value="text/html", token="text/html", title="HTML"))
     terms.append(
         SimpleTerm(
-            value='text/plain',
-            token='text/plain',
-            title='Plain text'))
+            value="text/x-web-markdown", token="text/x-web-markdown", title="Markdown"
+        )
+    )
     terms.append(
         SimpleTerm(
-            value='text/html',
-            token='text/html',
-            title='HTML'))
-    terms.append(
-        SimpleTerm(
-            value='text/x-web-markdown',
-            token='text/x-web-markdown',
-            title='Markdown'))
-    terms.append(
-        SimpleTerm(
-            value='text/x-web-intelligent',
-            token='text/x-web-intelligent',
-            title='Intelligent text'))
+            value="text/x-web-intelligent",
+            token="text/x-web-intelligent",
+            title="Intelligent text",
+        )
+    )
     return SimpleVocabulary(terms)
diff --git a/setup.cfg b/setup.cfg
index 5a698fc..e726c4c 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -11,3 +11,10 @@ universal = 1
 
 [zest.releaser]
 create-wheel = yes
+
+[isort]
+# black compatible Plone isort rules:
+profile = black
+force_alphabetical_sort = True
+force_single_line = True
+lines_after_imports = 2
diff --git a/setup.py b/setup.py
index 893470a..3b2c629 100644
--- a/setup.py
+++ b/setup.py
@@ -1,73 +1,62 @@
-# encoding: utf-8
-
 from setuptools import find_packages
 from setuptools import setup
 
 
-version = '4.0.0a7.dev0'
+version = "4.0.0a7.dev0"
 
 install_requires = [
-    'setuptools',
-    'plone.app.layout',
-    'plone.app.registry',
-    'plone.app.uuid',
-    'plone.app.z3cform',
-    'plone.indexer',
-    'plone.registry',
-    'plone.z3cform',
-    'six',
-    'ZODB3',
-    'zope.interface',
-    'zope.component',
-    'zope.annotation',
-    'zope.event',
-    'zope.container',
-    'zope.lifecycleevent',
-    'zope.site',
-    'z3c.form>=2.3.3',
+    "setuptools",
+    "plone.app.layout",
+    "plone.app.registry",
+    "plone.app.uuid",
+    "plone.app.z3cform",
+    "plone.base",
+    "plone.indexer",
+    "plone.z3cform",
+    "z3c.form>=2.3.3",
 ]
 
-setup(name='plone.app.discussion',
-      version=version,
-      description='Enhanced discussion support for Plone',
-      long_description=open('README.rst').read() + '\n' +
-      open('CHANGES.rst').read(),
-      classifiers=[
-          "Development Status :: 5 - Production/Stable",
-          "Environment :: Web Environment",
-          "Framework :: Plone",
-          "Framework :: Plone :: 6.0",
-          "Framework :: Plone :: Core",
-          "Framework :: Zope :: 5",
-          "License :: OSI Approved :: GNU General Public License v2 (GPLv2)",
-          "Operating System :: OS Independent",
-          "Programming Language :: Python",
-          "Programming Language :: Python :: 3.7",
-          "Programming Language :: Python :: 3.8",
-          "Programming Language :: Python :: 3.9",
-      ],
-      keywords='plone discussion',
-      author='Timo Stollenwerk - Plone Foundation',
-      author_email='plone-developers@lists.sourceforge.net',
-      url='https://pypi.org/project/plone.app.discussion',
-      license='GPL',
-      packages=find_packages(),
-      namespace_packages=['plone', 'plone.app'],
-      include_package_data=True,
-      zip_safe=False,
-      install_requires=install_requires,
-      extras_require={
-          'test': [
-              'plone.app.testing',
-              'plone.stringinterp',
-              'plone.contentrules',
-              'plone.app.contentrules',
-              'plone.app.contenttypes[test]',
-              'plone.app.robotframework',
-          ],
-      },
-      entry_points="""
+setup(
+    name="plone.app.discussion",
+    version=version,
+    description="Enhanced discussion support for Plone",
+    long_description=open("README.rst").read() + "\n" + open("CHANGES.rst").read(),
+    classifiers=[
+        "Development Status :: 5 - Production/Stable",
+        "Environment :: Web Environment",
+        "Framework :: Plone",
+        "Framework :: Plone :: 6.0",
+        "Framework :: Plone :: Core",
+        "Framework :: Zope :: 5",
+        "License :: OSI Approved :: GNU General Public License v2 (GPLv2)",
+        "Operating System :: OS Independent",
+        "Programming Language :: Python",
+        "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
+    ],
+    keywords="plone discussion",
+    author="Timo Stollenwerk - Plone Foundation",
+    author_email="plone-developers@lists.sourceforge.net",
+    url="https://pypi.org/project/plone.app.discussion",
+    license="GPL",
+    packages=find_packages(),
+    namespace_packages=["plone", "plone.app"],
+    include_package_data=True,
+    zip_safe=False,
+    install_requires=install_requires,
+    extras_require={
+        "test": [
+            "plone.app.testing",
+            "plone.stringinterp",
+            "plone.contentrules",
+            "plone.app.contentrules",
+            "plone.app.contenttypes[test]",
+            "plone.app.robotframework",
+        ],
+    },
+    entry_points="""
       [z3c.autoinclude.plugin]
       target = plone
       """,
-      )
+)