fix pylint warnings

native_client_sdk/src/build_tools/build_updater.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Build script to generate a new sdk_tools bundle.
 
 This script packages the files necessary to generate the SDK updater -- the
 tool users run to download new bundles, update existing bundles, etc.
 """
 
 import buildbot_common
 import build_utils
-import cStringIO
 import optparse
 import os
-import re
 import sys
 
 SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
 SDK_SRC_DIR = os.path.dirname(SCRIPT_DIR)
 SDK_DIR = os.path.dirname(SDK_SRC_DIR)
 SRC_DIR = os.path.dirname(SDK_DIR)
 NACL_DIR = os.path.join(SRC_DIR, 'native_client')
 CYGTAR = os.path.join(NACL_DIR, 'build', 'cygtar.py')
 
 sys.path.append(os.path.join(SDK_SRC_DIR, 'tools'))
@@ skipping 76 matching lines @@
     out_dir: The output directory containing the scripts to update.
     revision_number: The revision number as an integer, or None to use the
         current Chrome revision (as retrieved through svn/git).
   """
   if revision_number is None:
     revision_number = build_utils.ChromeRevision()
 
   SDK_UPDATE_MAIN = os.path.join(out_dir,
       'nacl_sdk/sdk_tools/sdk_update_main.py')
 
-  file = open(SDK_UPDATE_MAIN, 'r').read().replace(
+  contents = open(SDK_UPDATE_MAIN, 'r').read().replace(
       '{REVISION}', str(revision_number))
-  open(SDK_UPDATE_MAIN, 'w').write(file)
+  open(SDK_UPDATE_MAIN, 'w').write(contents)
 
 
 def BuildUpdater(out_dir, revision_number=None):
   """Build naclsdk.zip and sdk_tools.tgz in |out_dir|.
 
   Args:
     out_dir: The output directory.
     revision_number: The revision number of this updater, as an integer. Or
         None, to use the current Chrome revision."""
   buildbot_common.BuildStep('Create Updater')
 
   out_dir = os.path.abspath(out_dir)
 
   # Build SDK directory
   buildbot_common.RemoveDir(os.path.join(out_dir, 'nacl_sdk'))
 
   updater_files = MakeUpdaterFilesAbsolute(out_dir)
-  out_files = [out_file for in_file, out_file in updater_files]
+  out_files = [out_file for _, out_file in updater_files]
 
   CopyFiles(updater_files)
   UpdateRevisionNumber(out_dir, revision_number)
 
   # Make zip
   buildbot_common.RemoveFile(os.path.join(out_dir, 'nacl_sdk.zip'))
   buildbot_common.Run([sys.executable, oshelpers.__file__, 'zip',
                       'nacl_sdk.zip'] + out_files,
                       cwd=out_dir)
 
@@ skipping 12 matching lines @@
   parser = optparse.OptionParser()
   parser.add_option('-o', '--out', help='output directory',
       dest='out_dir', default='out')
   options, args = parser.parse_args(args[1:])
 
   BuildUpdater(options.out_dir)
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))