Add support for empty files, __init__.py is a common example.

apply_issue.py

 #!/usr/bin/env python
 # Copyright (c) 2011 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.
 
 """Applies an issue from Rietveld.
 """
 
 import logging
 import optparse
 import os
 import sys
 
 import breakpad  # pylint: disable=W0611
 
 import checkout
 import fix_encoding
 import rietveld
 import scm
 
 
 def main():
   parser = optparse.OptionParser(description=sys.modules[__name__].__doc__)
   parser.add_option(
-      '-v', '--verbose', action='count', help='Prints debugging infos')
+      '-v', '--verbose', action='count', default=0,
+      help='Prints debugging infos')
   parser.add_option(
       '-i', '--issue', type='int', help='Rietveld issue number')
   parser.add_option(
       '-p', '--patchset', type='int', help='Rietveld issue\'s patchset number')
   parser.add_option(
       '-r',
       '--root_dir',
       default=os.getcwd(),
       help='Root directory to apply the patch')
   parser.add_option(
       '-s',
       '--server',
       default='http://codereview.chromium.org',
       help='Rietveld server')
   options, args = parser.parse_args()
-  LOG_FORMAT = '%(levelname)s %(filename)s(%(lineno)d): %(message)s'
-  if not options.verbose:
-    logging.basicConfig(level=logging.WARNING, format=LOG_FORMAT)
-  elif options.verbose == 1:
-    logging.basicConfig(level=logging.INFO, format=LOG_FORMAT)
-  elif options.verbose > 1:
-    logging.basicConfig(level=logging.DEBUG, format=LOG_FORMAT)
+  logging.basicConfig(
+      format='%(levelname)s %(filename)s(%(lineno)d): %(message)s',
+      level=[logging.WARNING, logging.INFO, logging.DEBUG][
+          min(2, options.verbose)])
   if args:
     parser.error('Extra argument(s) "%s" not understood' % ' '.join(args))
   if not options.issue:
     parser.error('Require --issue')
 
   obj = rietveld.Rietveld(options.server, None, None)
 
   if not options.patchset:
     options.patchset = obj.get_issue_properties(
         options.issue, False)['patchsets'][-1]
@@ skipping 12 matching lines @@
     parser.error('Couldn\'t determine the scm')
 
   # Apply the patch.
   scm_obj.apply_patch(patchset)
   return 0
 
 
 if __name__ == "__main__":
   fix_encoding.fix_encoding()
   sys.exit(main())