Fix pylint warnings in webkitpy/common/.

third_party/WebKit/Tools/Scripts/webkitpy/common/system/filesystem.py

 # Copyright (C) 2010 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 60 matching lines @@
 
     def copyfile(self, source, destination):
         shutil.copyfile(source, destination)
 
     def dirname(self, path):
         return os.path.dirname(path)
 
     def exists(self, path):
         return os.path.exists(path)
 
-    def files_under(self, path, dirs_to_skip=[], file_filter=None):
+    def files_under(self, path, dirs_to_skip=None, file_filter=None):
         """Return the list of all files under the given path in topdown order.
 
         Args:
             dirs_to_skip: a list of directories to skip over during the
                 traversal (e.g., .svn, resources, etc.)
             file_filter: if not None, the filter will be invoked
                 with the filesystem object and the dirname and basename of
                 each file found. The file is included in the result if the
                 callback returns True.
         """
-        def filter_all(fs, dirpath, basename):
+        dirs_to_skip = dirs_to_skip or []
+
+        def filter_all(*_):
             return True
 
         file_filter = file_filter or filter_all
         files = []
         if self.isfile(path):
             if file_filter(self, self.dirname(path), self.basename(path)):
                 files.append(path)
             return files
 
         if self.basename(path) in dirs_to_skip:
@@ skipping 50 matching lines @@
             def __init__(self, **kwargs):
                 self._kwargs = kwargs
                 self._directory_path = tempfile.mkdtemp(**self._kwargs)
 
             def __str__(self):
                 return self._directory_path
 
             def __enter__(self):
                 return self._directory_path
 
-            def __exit__(self, type, value, traceback):
+            def __exit__(self, *_):
                 # Only self-delete if necessary.
-
                 # FIXME: Should we delete non-empty directories?
                 if os.path.exists(self._directory_path):
                     os.rmdir(self._directory_path)
 
         return TemporaryDirectory(**kwargs)
 
     def maybe_make_directory(self, *path):
         """Create the specified directory if it doesn't already exist."""
         try:
             os.makedirs(self.join(*path))
         except OSError as e:
             if e.errno != errno.EEXIST:
                 raise
 
     def move(self, source, destination):
         shutil.move(source, destination)
 
     def mtime(self, path):
         return os.stat(path).st_mtime
 
     def normpath(self, path):
         return os.path.normpath(path)
 
     def open_binary_tempfile(self, suffix):
         """Create, open, and return a binary temp file. Returns a tuple of the file and the name."""
         temp_fd, temp_name = tempfile.mkstemp(suffix)
-        f = os.fdopen(temp_fd, 'wb')
-        return f, temp_name
+        fh = os.fdopen(temp_fd, 'wb')
+        return fh, temp_name
 
     def open_binary_file_for_reading(self, path):
         return codecs.open(path, 'rb')
 
     def read_binary_file(self, path):
         """Return the contents of the file at the given path as a byte string."""
-        with file(path, 'rb') as f:
-            return f.read()
+        with file(path, 'rb') as fh:
+            return fh.read()
 
     def write_binary_file(self, path, contents):
-        with file(path, 'wb') as f:
-            f.write(contents)
+        with file(path, 'wb') as fh:
+            fh.write(contents)
 
     def open_text_file_for_reading(self, path):
         # Note: There appears to be an issue with the returned file objects
         # not being seekable. See
         # http://stackoverflow.com/questions/1510188/can-seek-and-tell-work-with-utf-8-encoded-documents-in-python
         # .
         return codecs.open(path, 'r', 'utf8')
 
     def open_text_file_for_writing(self, path):
         return codecs.open(path, 'w', 'utf8')
@@ skipping 54 matching lines @@
     def split(self, path):
         """Return (dirname, basename + '.' + ext)"""
         return os.path.split(path)
 
     def splitext(self, path):
         """Return (dirname + os.sep + basename, '.' + ext)"""
         return os.path.splitext(path)
 
     def make_executable(self, file_path):
         os.chmod(file_path, stat.S_IRUSR | stat.S_IWUSR | stat.S_IXUSR | stat.S_IRGRP | stat.S_IXGRP)