add PRESUBMIT for native_client_sdk.

native_client_sdk/src/build_tools/sdk_tools/sdk_update_main.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.
 
 '''A simple tool to update the Native Client SDK to the latest version'''
 
 import cStringIO
 import cygtar
 import json
@@ skipping 30 matching lines @@
   sources - Manage external package sources
 
 Example Usage:
   naclsdk info pepper_canary
   naclsdk list
   naclsdk update --force pepper_17
   naclsdk install recommended
   naclsdk help update
   naclsdk sources --list'''
 
-CONFIG_FILENAME='naclsdk_config.json'
-MANIFEST_FILENAME='naclsdk_manifest2.json'
-SDK_TOOLS='sdk_tools'  # the name for this tools directory
-USER_DATA_DIR='sdk_cache'
+CONFIG_FILENAME = 'naclsdk_config.json'
+MANIFEST_FILENAME = 'naclsdk_manifest2.json'
+SDK_TOOLS = 'sdk_tools'  # the name for this tools directory
+USER_DATA_DIR = 'sdk_cache'
 
 HTTP_CONTENT_LENGTH = 'Content-Length'  # HTTP Header field for content length
 
 
 #------------------------------------------------------------------------------
 # General Utilities
 
 
 _debug_mode = False
 _quiet_mode = False
@@ skipping 62 matching lines @@
     # If the installer has extension 'exe', assume it's a Windows NSIS-style
     # installer that handles silent (/S) and relocated (/D) installs.
     command = [installer, '/S', '/D=%s' % outdir]
     subprocess.check_call(command)
   else:
     os.mkdir(outdir)
     tar_file = None
     curpath = os.getcwd()
     try:
       tar_file = cygtar.CygTar(installer, 'r', verbose=True)
-      if outdir: os.chdir(outdir)
+      if outdir:
+        os.chdir(outdir)
       tar_file.Extract()
     finally:
       if tar_file:
         tar_file.Close()
       os.chdir(curpath)
 
 
 class ProgressFunction(object):
   '''Create a progress function for a file with a given size'''
 
@@ skipping 47 matching lines @@
       InfoPrint('Downloading %s' % archive.url)
       sha1, size = manifest_util.DownloadAndComputeHash(
           from_stream,
           to_stream=to_stream,
           progress_func=progress_function)
       if size != content_length:
         raise Error('Download size mismatch for %s.\n'
                     'Expected %s bytes but got %s' %
                     (archive.url, content_length, size))
     finally:
-      if from_stream: from_stream.close()
+      if from_stream:
+        from_stream.close()
   return sha1, size
 
 
 def LoadFromFile(path, obj):
   '''Returns a manifest loaded from the JSON file at |path|.
 
   If the path does not exist or is invalid, returns unmodified object.'''
   methodlist = [m for m in dir(obj) if callable(getattr(obj, m))]
   if 'LoadDataFromString' not in methodlist:
     return obj
@@ skipping 12 matching lines @@
 def LoadManifestFromURLs(urls):
   '''Returns a manifest loaded from |urls|, merged into one manifest.'''
   manifest = manifest_util.SDKManifest()
   for url in urls:
     try:
       url_stream = UrlOpen(url)
     except urllib2.URLError as e:
       raise Error('Unable to open %s. [%s]' % (url, e))
 
     manifest_stream = cStringIO.StringIO()
-    sha1, size = manifest_util.DownloadAndComputeHash(url_stream,
-                                                      manifest_stream)
+    manifest_util.DownloadAndComputeHash(url_stream, manifest_stream)
     temp_manifest = manifest_util.SDKManifest()
     temp_manifest.LoadDataFromString(manifest_stream.getvalue())
 
     manifest.MergeManifest(temp_manifest)
 
   def BundleFilter(bundle):
     # Only add this bundle if it's supported on this platform.
     return bundle.GetHostOSArchive()
 
   manifest.FilterBundles(BundleFilter)
@@ skipping 234 matching lines @@
           write manifest to disk.  Use locks.
         else:
           InfoPrint('bundle is up-to-date')
 
   Targets:
     recommended: (default) Install/Update all recommended components
     all:         Install/Update all available components
     bundle_name: Install/Update only the given bundle
   '''
   DebugPrint("Running Update command with: %s, %s" % (options, argv))
-  ALL='all'  # Update all bundles
-  RECOMMENDED='recommended'  # Only update the bundles with recommended=yes
+  ALL = 'all'  # Update all bundles
+  RECOMMENDED = 'recommended'  # Only update the bundles with recommended=yes
 
   parser = optparse.OptionParser(usage=Update.__doc__)
   parser.add_option(
       '-F', '--force', dest='force',
       default=False, action='store_true',
       help='Force updating existing components that already exist')
   (update_options, args) = parser.parse_args(argv)
 
   if len(args) == 0:
     args = [RECOMMENDED]
@@ skipping 23 matching lines @@
           'Ignoring manual update request.')
       continue
 
     if not (bundle.name in args or
             ALL in args or (RECOMMENDED in args and
                             bundle[RECOMMENDED] == 'yes')):
       continue
     def UpdateBundle():
       '''Helper to install a bundle'''
       archive = bundle.GetHostOSArchive()
-      (scheme, host, path, _, _, _) = urlparse.urlparse(archive['url'])
+      (_, _, path, _, _, _) = urlparse.urlparse(archive['url'])
       dest_filename = os.path.join(options.user_data_dir, path.split('/')[-1])
       sha1, size = DownloadArchiveToFile(archive, dest_filename)
       if sha1 != archive.GetChecksum():
         raise Error("SHA1 checksum mismatch on '%s'.  Expected %s but got %s" %
                     (bundle.name, archive.GetChecksum(), sha1))
       if size != archive.size:
         raise Error("Size mismatch on Archive.  Expected %s but got %s bytes" %
                     (archive.size, size))
       InfoPrint('Updating bundle %s to version %s, revision %s' % (
                 (bundle.name, bundle.version, bundle.revision)))
@@ skipping 41 matching lines @@
       default=None,
       help='Add additional package source')
   parser.add_option(
       '-r', '--remove', dest='url_to_remove',
       default=None,
       help='Remove package source (use \'all\' for all additional sources)')
   parser.add_option(
       '-l', '--list', dest='do_list',
       default=False, action='store_true',
       help='List additional package sources')
-  (source_options, args) = parser.parse_args(argv)
+  source_options, _ = parser.parse_args(argv)
 
   write_config = False
   if source_options.url_to_add:
     config.AddSource(source_options.url_to_add)
     write_config = True
   elif source_options.url_to_remove:
     if source_options.url_to_remove == 'all':
       config.RemoveAllSources()
     else:
       config.RemoveSource(source_options.url_to_remove)
@@ skipping 134 matching lines @@
 
   return 0  # Success
 
 
 if __name__ == '__main__':
   try:
     sys.exit(main(sys.argv[1:]))
   except Error as error:
     print "Error: %s" % error
     sys.exit(1)