util.py 文件源码

def try_serialize_handler(handler):
  """Try to serialize map/reduce handler.

  Args:
    handler: handler function/instance. Handler can be a function or an
      instance of a callable class. In the latter case, the handler will
      be serialized across slices to allow users to save states.

  Returns:
    serialized handler string or None.
  """
  if (isinstance(handler, types.InstanceType) or
      (isinstance(handler, object) and
       not inspect.isfunction(handler) and
       not inspect.ismethod(handler)) and
      hasattr(handler, "__call__")):
    return pickle.dumps(handler)
  return None