Python“序列化”未定义

Question

您能帮我弄清楚如何解决此问题或如何声明变量吗？这只是我的代码的一部分，而是发生错误的部分。

 def send_message(self, message, source = "Python Client", type = serialize.Message.INFO_MESSAGE):
     md = Command.RTDE_TEXT_MESSAGE
    fmt = '>B%dsB%dsB' % (len(message), len(source))
    payload = struct.pack(fmt, len(message), message, len(source), source, type)
    return self.__sendall(cmd, payload)

这是我遇到的错误

File "..\rtde\rtde.py", line 187, in RTDE
  def send_message(self, message, source = "Python Client", type = serialize.Message.INFO_MESSAGE):
NameError: name 'serialize' is not defined