Fix lint errors to enable stricter PyLint rules

tools-webrtc/ios/generate_licenses.py

 #!/usr/bin/python
 
 #  Copyright 2016 The WebRTC project authors. All Rights Reserved.
 #
 #  Use of this source code is governed by a BSD-style license
 #  that can be found in the LICENSE file in the root of the source
 #  tree. An additional intellectual property rights grant can be found
 #  in the file PATENTS.  All contributing project authors may
 #  be found in the AUTHORS file in the root of the source tree.
 
@@ skipping 19 matching lines @@
     'usrsctp': ['third_party/usrsctp/LICENSE'],
     'webrtc': ['webrtc/LICENSE', 'webrtc/LICENSE_THIRD_PARTY'],
     'libvpx': ['third_party/libvpx/source/libvpx/LICENSE'],
     'libyuv': ['third_party/libyuv/LICENSE'],
 }
 
 SCRIPT_DIR = os.path.dirname(os.path.realpath(sys.argv[0]))
 CHECKOUT_ROOT = os.path.abspath(os.path.join(SCRIPT_DIR, os.pardir, os.pardir))
 WEBRTC_ROOT = os.path.join(CHECKOUT_ROOT, 'webrtc')
 
+
 def GetThirdPartyLibraries(buildfile_dir, target_name):
-  def extractLibName(s):
+  def ExtractLibName(string_list):
     # Sample input:
     # ["   //third_party/usrsctp:usrsctp", "    //webrtc:webrtc_common"]
     # Sample output:
     # ["usrsctp"]
-    return re.sub(r'\(.*\)', '', s).strip().split(os.path.sep)[-1].split(':')[0]
+    return re.sub(r'\(.*\)', '', string_list).strip().split(
+        os.path.sep)[-1].split(':')[0]
   output = subprocess.check_output(
     ["gn", "desc", buildfile_dir, target_name, '--all']) .split(os.linesep)
-  return [extractLibName(x) for x in output if re.search(r'third_party', x)]
+  return [ExtractLibName(x) for x in output if re.search(r'third_party', x)]
 
 
 class LicenseBuilder(object):
 
   def __init__(self, buildfile_dirs, target_name):
     self.buildfile_dirs = buildfile_dirs
     self.target_name = target_name
 
   def GenerateLicenseText(self, output_dir):
     # Get a list of third_party libs from gn. For fat libraries we must consider
@@ skipping 45 matching lines @@
           output_license_file.write(license_text)
           output_license_file.write('\n')
       output_license_file.write('</pre>\n')
 
     output_license_file.write('</body>\n')
     output_license_file.write('</html>')
     output_license_file.close()
     return 0
 
 
-if __name__ == '__main__':
+def main():
   parser = argparse.ArgumentParser(description='Generate WebRTC LICENSE.html')
   parser.add_argument('target_name',
                       help='Name of the GN target to generate a license for')
   parser.add_argument('output_dir',
                       help='Directory to output LICENSE.html to.')
   parser.add_argument('buildfile_dirs', nargs="+",
                       help='Directories containing gn generated ninja files')
   args = parser.parse_args()
   builder = LicenseBuilder(args.buildfile_dirs, args.target_name)
   sys.exit(builder.GenerateLicenseText(args.output_dir))
+
+
+if __name__ == '__main__':
+  main()