python - rabbitMQ消息的存储方式

Question

我正在使用带有 python 的 RabbitMQ 服务器向服务器发送和接收消息这是我用来向代码发送消息的代码。

import numpy as np
import pandas as pd
import pika

connection = pika.BlockingConnection(pika.ConnectionParameters(
             host='localhost'))
channel = connection.channel()
channel.queue_declare(queue='Q1')
message = 'Hello World'
channel.basic_publish(exchange='',
                      routing_key='Q1',
                      body=message)
# Printing the Sending Confirmation of ID
print(" [x] Sent %r" % message)

connection.close()

输出:

[x] Sent 'Hello World' 

这是我用来从队列接收消息的代码

import pika
import sys

connection = pika.BlockingConnection(pika.ConnectionParameters(host='localhost'))
channel = connection.channel()
channel.queue_declare(queue='Q1')
def callback(ch, method, properties, body):
    print(" [x] Received %r" % body)

channel.basic_consume(callback, queue='Q1', no_ack=True)
channel.start_consuming()

输出:

[x] Received 'Hello World'

问题是我想将此消息(即“Hello World”)保存到一个变量中，然后在我的程序中使用它

但是我无法保存消息。

如何将它保存到变量中。Multiple Messages in the queue 的解决方案是什么

Answer 1

The problem is I want to save this message i.e. "Hello World" to a variable and then use it in my program

您已经有了一个可以在程序中使用的变量 - body。如果您想将基础架构代码(即RabbitMq/pika)与业务逻辑分离，那么您只需声明另一个函数并传递body 到它。

def processing_function(message_received):
    print(" [x] Received %r" % message_received)

def callback(ch, method, properties, body):
    processing_function(body)

想法是，一旦收到消息，pika 就会调用callback，然后将body 传递给执行计算的processing_function。

如果您难以理解回调函数，我建议您阅读 this首先。