您的XMLRPC服务器出现故障，因为它无法封送None.您需要将allow_none=True添加到服务器构造函数中:

Your XMLRPC server is raising a fault since it cannot marshal None. You need to add allow_none=True to the server constructor:

server = SimpleXMLRPCServer(("127.0.0.1", 8000),
                        requestHandler=RequestHandler, 
                        allow_none=True)