client.py 文件源码

def add_watch_callback(self, *args, **kwargs):
        """
        Watch a key or range of keys and call a callback on every event.

        If timeout was declared during the client initialization and
        the watch cannot be created during that time the method raises
        a ``WatchTimedOut`` exception.

        :param key: key to watch
        :param callback: callback function

        :returns: watch_id. Later it could be used for cancelling watch.
        """
        try:
            return self.watcher.add_callback(*args, **kwargs)
        except queue.Empty:
            raise exceptions.WatchTimedOut()