code: def _create_file_if_needed(self):
          
          if not os.path.exists(self._filename):
              old_umask = os.umask(0o177)
              try:
                  open(self._filename, 'a+b').close()
              finally:
                  os.umask(old_umask)
docs: Create an empty file if necessary.
  
          This method will not initialize the file. Instead it implements a
          simple version of "touch" to ensure the file has been created.