如何删除rabbitmq中的消息（pika）

请遵循这样的消息：

https://www.rabbitmq.com/tutorials/tutorial-two-python.html

最幸运的你是不是发送ACK：

def callback(ch, method, properties, body): 
    print " [x] Received %r" % (body,) 
    time.sleep(body.count('.')) 
    print " [x] Done" 
    ch.basic_ack(delivery_tag = method.delivery_tag) ### <--- this one 
channel.basic_consume(callback, 
         queue='hello')