Mine

    def dispatch(self, sender, payload):
        try:
            msg_type, data = payload
        except ValueError:
            return logger.error("Invalid message format", exc_info=True)

        f = getattr(self, 'event_%s' % msg_type, None)
        if not f:
            return logger.error("Invalid rpc: %s" % msg_type)
        f(sender, data)