__init__.py 文件源码

def add_listener(self, keys: Union[Key, Set[Key]], callback: ListenerCallback) -> None:
        '''
        Attach ``callback`` to one or more keys. If more than one key is provided, the callback will be
        reading all messages from one queue, and they are guaranteed to arrive in the same order they were published.

        :param keys: One key, or a set of keys.
        '''
        keys, sub_id = self._get_listener_subscription(keys, callback)
        for key in keys:
            self.subscribe(key, sub_id)

        async def consumer() -> None:
            key, msg = await self.consume(sub_id)
            callback(key, msg)

        loop = aiopubsub.loop.Loop(consumer, delay = None)
        loop.start()
        self._listeners[sub_id] = Listener(loop, keys)