nsq/event.py
def on(self, name, callback):
        """
        Listen for the named event with the specified callback.

        :param name: the name of the event
        :type name: string

        :param callback: the callback to execute when the event is triggered
        :type callback: callable
        """
        assert callable(callback), 'callback is not callable'
        if callback in self.__listeners[name]:
            raise DuplicateListenerError
        self.__listeners[name].append(callback)
def on(self, name, callback):
        """
        Listen for the named event with the specified callback.

        :param name: the name of the event
        :type name: string

        :param callback: the callback to execute when the event is triggered
        :type callback: callable
        """
        assert callable(callback), 'callback is not callable'
        if callback in self.__listeners[name]:
            raise DuplicateListenerError
        self.__listeners[name].append(callback)
Listen for the named event with the specified callback.

        :param name: the name of the event
        :type name: string

        :param callback: the callback to execute when the event is triggered
        :type callback: callable