Fix issues reported by flake8-comprehensions

python/test_requirements.txt

@@ -1,4 +1,5 @@
 flake8                >= 3.0.0
+flake8-comprehensions >= 1.4.1
 mock                  >= 1.0.1
 nose                  >= 1.3.7
 PyHamcrest            >= 1.8.0

python/ycm/buffer.py

@@ -27,9 +27,8 @@ from ycm.client.event_notification import EventNotification
 from ycm.diagnostic_interface import DiagnosticInterface
 
 
-DIAGNOSTIC_UI_FILETYPES = set( [ 'cpp', 'cs', 'c', 'objc', 'objcpp',
-                                 'typescript' ] )
-DIAGNOSTIC_UI_ASYNC_FILETYPES = set( [ 'java' ] )
+DIAGNOSTIC_UI_FILETYPES = { 'cpp', 'cs', 'c', 'objc', 'objcpp', 'typescript' }
+DIAGNOSTIC_UI_ASYNC_FILETYPES = { 'java' }
 
 
 # Emulates Vim buffer
@@ -131,8 +130,7 @@ class BufferDict( dict ):
     new_value = self[ key ] = Buffer(
       key,
       self._user_options,
-      any( [ x in DIAGNOSTIC_UI_ASYNC_FILETYPES
-             for x in
-             vimsupport.GetBufferFiletypes( key ) ] ) )
+      any( x in DIAGNOSTIC_UI_ASYNC_FILETYPES
+           for x in vimsupport.GetBufferFiletypes( key ) ) )
 
     return new_value

python/ycm/client/completion_request.py

@@ -181,7 +181,7 @@ def _FilterToMatchingCompletions( completed_item, completions ):
       return ( ToUnicode( completed_item.get( key, "" ) ) ==
                ToUnicode( item.get( key, "" ) ) )
 
-    if all( [ matcher( i ) for i in match_keys ] ):
+    if all( matcher( i ) for i in match_keys ):
       matched_completions.append( completion )
   return matched_completions
 

python/ycm/syntax_parse.py

@@ -45,20 +45,20 @@ SYNTAX_REGION_ARGUMENT_REGEX = re.compile(
   r"^(?:matchgroup|start)=.*$")
 
 # See ":h syn-nextgroup".
-SYNTAX_NEXTGROUP_ARGUMENTS = set([
+SYNTAX_NEXTGROUP_ARGUMENTS = {
   'skipwhite',
   'skipnl',
   'skipempty'
-])
+}
 
 # These are the parent groups from which we want to extract keywords.
-ROOT_GROUPS = set([
+ROOT_GROUPS = {
   'Boolean',
   'Identifier',
   'Statement',
   'PreProc',
   'Type'
-])
+}
 
 
 class SyntaxGroup( object ):

python/ycm/vimsupport.py

@@ -670,7 +670,7 @@ def CurrentFiletypesEnabled( disabled_filetypes ):
   filetypes and values are unimportant. The special key '*' matches all
   filetypes."""
   return ( '*' not in disabled_filetypes and
-           not any( [ x in disabled_filetypes for x in CurrentFiletypes() ] ) )
+           not any( x in disabled_filetypes for x in CurrentFiletypes() ) )
 
 
 def GetBufferFiletypes( bufnr ):

python/ycm/youcompleteme.py

@@ -357,8 +357,8 @@ class YouCompleteMe( object ):
 
 
   def NativeFiletypeCompletionAvailable( self ):
-    return any( [ self.FiletypeCompleterExistsForFiletype( x ) for x in
-                  vimsupport.CurrentFiletypes() ] )
+    return any( self.FiletypeCompleterExistsForFiletype( x ) for x in
+                vimsupport.CurrentFiletypes() )
 
 
   def NativeFiletypeCompletionUsable( self ):
@@ -498,9 +498,9 @@ class YouCompleteMe( object ):
 
 
   def DiagnosticUiSupportedForCurrentFiletype( self ):
-    return any( [ x in DIAGNOSTIC_UI_FILETYPES or
+    return any( x in DIAGNOSTIC_UI_FILETYPES or
                 x in DIAGNOSTIC_UI_ASYNC_FILETYPES
-                  for x in vimsupport.CurrentFiletypes() ] )
+                for x in vimsupport.CurrentFiletypes() )
 
 
   def ShouldDisplayDiagnostics( self ):