def _create_file_if_needed(self):
    if not os.path.exists(self._filename):
      old_umask = os.umask(0177)
      try:
        open(self._filename, 'a+b').close()
      finally:
        os.umask(old_umask)
Create an empty file if necessary.
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/google-api-python-client/oauth2client/file.py/Storage._create_file_if_needed