diff --git a/plone/app/discussion/comment.py b/plone/app/discussion/comment.py
index 97f2b17..917646c 100644
--- a/plone/app/discussion/comment.py
+++ b/plone/app/discussion/comment.py
@@ -235,6 +235,7 @@ def notify_content_object(obj, event):
                                     '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.
@@ -244,6 +245,7 @@ def notify_content_object_deleted(obj, event):
         while conversation:
             del conversation[conversation.keys()[0]]
 
+
 def notify_comment_added(obj, event):
     """ Notify custom discussion events when a comment is added or replied
     """
@@ -253,6 +255,7 @@ def notify_comment_added(obj, event):
         return notify(ReplyAddedEvent(context, obj))
     return notify(CommentAddedEvent(context, obj))
 
+
 def notify_comment_removed(obj, event):
     """ Notify custom discussion events when a comment or reply is removed
     """
@@ -262,6 +265,7 @@ def notify_comment_removed(obj, event):
         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.
     """
diff --git a/plone/app/discussion/contentrules.py b/plone/app/discussion/contentrules.py
index dfa00fc..8dc082b 100644
--- a/plone/app/discussion/contentrules.py
+++ b/plone/app/discussion/contentrules.py
@@ -23,6 +23,7 @@ def execute_comment(event):
     """
     execute(event.object, event)
 
+
 class CommentSubstitution(BaseSubstitution):
     """ Comment string substitution
     """
@@ -41,6 +42,7 @@ class CommentSubstitution(BaseSubstitution):
         """
         return self.event.comment
 
+
 class Id(CommentSubstitution):
     """ Comment id string substitution
     """
@@ -52,6 +54,7 @@ class Id(CommentSubstitution):
         """
         return getattr(self.comment, 'comment_id', u'')
 
+
 class Text(CommentSubstitution):
     """ Comment text
     """
@@ -63,6 +66,7 @@ class Text(CommentSubstitution):
         """
         return getattr(self.comment, 'text', u'')
 
+
 class AuthorUserName(CommentSubstitution):
     """ Comment author user name string substitution
     """
@@ -74,6 +78,7 @@ class AuthorUserName(CommentSubstitution):
         """
         return getattr(self.comment, 'author_username', u'')
 
+
 class AuthorFullName(CommentSubstitution):
     """ Comment author full name string substitution
     """
@@ -85,6 +90,7 @@ class AuthorFullName(CommentSubstitution):
         """
         return getattr(self.comment, 'author_name', u'')
 
+
 class AuthorEmail(CommentSubstitution):
     """ Comment author email string substitution
     """
diff --git a/plone/app/discussion/events.py b/plone/app/discussion/events.py
index 2ec918b..aefe2ab 100644
--- a/plone/app/discussion/events.py
+++ b/plone/app/discussion/events.py
@@ -24,21 +24,25 @@ class DiscussionEvent(object):
         request = context.REQUEST
         request.set('event', self)
 
+
 class CommentAddedEvent(DiscussionEvent):
     """ Event to be triggered when a Comment is added
     """
     implements(ICommentAddedEvent)
 
+
 class CommentRemovedEvent(DiscussionEvent):
     """ Event to be triggered when a Comment is removed
     """
     implements(ICommentRemovedEvent)
 
+
 class ReplyAddedEvent(DiscussionEvent):
     """ Event to be triggered when a Comment reply is added
     """
     implements(IReplyAddedEvent)
 
+
 class ReplyRemovedEvent(DiscussionEvent):
     """ Event to be triggered when a Comment reply is removed
     """
diff --git a/plone/app/discussion/interfaces.py b/plone/app/discussion/interfaces.py
index 20b6afe..2d15935 100644
--- a/plone/app/discussion/interfaces.py
+++ b/plone/app/discussion/interfaces.py
@@ -371,22 +371,27 @@ class ICommentingTool(Interface):
 # Custom events
 #
 
+
 class IDiscussionEvent(IObjectEvent):
     """ Discussion custom event
     """
 
+
 class ICommentAddedEvent(IDiscussionEvent):
     """ Comment added
     """
 
+
 class ICommentRemovedEvent(IDiscussionEvent):
     """ Comment removed
     """
 
+
 class IReplyAddedEvent(IDiscussionEvent):
     """ Comment reply added
     """
 
+
 class IReplyRemovedEvent(IDiscussionEvent):
     """ Comment reply removed
     """
diff --git a/plone/app/discussion/tests/test_contentrules.py b/plone/app/discussion/tests/test_contentrules.py
index 51e9254..8d28bf0 100644
--- a/plone/app/discussion/tests/test_contentrules.py
+++ b/plone/app/discussion/tests/test_contentrules.py
@@ -44,7 +44,6 @@ class CommentContentRulesTest(unittest.TestCase):
         conversation = IConversation(self.document)
         conversation.addComment(comment)
 
-
     def testEventTypesMarked(self):
         self.assertTrue(IRuleEventType.providedBy(ICommentAddedEvent))
         self.assertTrue(IRuleEventType.providedBy(ICommentRemovedEvent))
diff --git a/plone/app/discussion/tests/test_events.py b/plone/app/discussion/tests/test_events.py
index 431df14..e72de0c 100644
--- a/plone/app/discussion/tests/test_events.py
+++ b/plone/app/discussion/tests/test_events.py
@@ -27,20 +27,29 @@ class EventsRegistry(object):
 #
 # Fake event handlers
 #
+
+
 def comment_added(doc, evt):
     EventsRegistry.commentAdded = True
 
+
 def comment_removed(doc, evt):
     EventsRegistry.commentRemoved = True
 
+
 def reply_added(doc, evt):
     EventsRegistry.replyAdded = True
 
+
 def reply_removed(doc, evt):
     EventsRegistry.replyRemoved = True
+
+
 #
 # Tests
 #
+
+
 class CommentEventsTest(unittest.TestCase):
     """ Test custom comments events
     """