消息队列 RocketMQ 5.x版本提供顺序消息（FIFO消息）供您使用。在顺序消息模型中，您需要严格按照顺序来发布和消费消息。本文提供使用PYTHON SDK 收发顺序消息的示例代码供您参考。

顺序消息分为两类，全局顺序消息和分区顺序消息。区别仅为队列数量不同，代码没有区别。

• 全局顺序：
  对于指定的一个 Topic，所有消息的生产和消费需要遵循一定的顺序，消息的消费顺序必须和生产顺序一致，即需要严格的先入先出 FIFO（First In First Out）的顺序进行发布和消费。
• 分区顺序：
  对于指定的一个 Topic，其中每一个分区的消息生产与消费是有序的，同一个队列内的消息按照严格的 FIFO 顺序进行发布和订阅。消息投递到哪一个分区由消息的 messageGroup 来进行区分

注意顺序消息，需要在控制台申请顺序类型的topic以及顺序类型的group

发送顺序消息的示例代码如下。

from rocketmq import ClientConfiguration, Credentials, Message, Producer

if __name__ == '__main__':
    # 火山接入点
    endpoints = "rocketmq-xxxx:8080"
    credentials = Credentials()
    # if auth enable, 火山ak,sk
    credentials = Credentials("xxxx", "xxxx")
    config = ClientConfiguration(endpoints, credentials)
    topic = "xxxx" # 顺序topic
    producer = Producer(config, (topic,))

    try:
        producer.startup()
        try:
            msg = Message()
            msg.topic = topic
            msg.message_group = "messageGroup" # 顺序topic group
            msg.body = "hello, rocketmq.".encode('utf-8')
            msg.tag = "rocketmq-send-fifo-message"
            msg.keys = "send_sync"
            msg.add_property("send", "sync")
            res = producer.send(msg)
            print(f"{producer.__str__()} send message success. {res}")
            producer.shutdown()
            print(f"{producer.__str__()} shutdown.")
        except Exception as e:
            print(f"normal producer example raise exception: {e}")
            producer.shutdown()
    except Exception as e:
        print(f"{producer.__str__()} startup raise exception: {e}")
        producer.shutdown()

订阅顺序消息的示例代码如下，要注意group一定是申请的顺序类型

from rocketmq import ClientConfiguration, Credentials, SimpleConsumer

if __name__ == '__main__':
    # 火山接入点    
    endpoints = "rocketmq-xxxx:8080"
    credentials = Credentials()
    # if auth enable, 火山ak,sk
    credentials = Credentials("xxxx", "xxxx")
    config = ClientConfiguration(endpoints, credentials)
    topic = "xxxx" # topic名称
    simple_consumer = SimpleConsumer(config, "groupName") # group name
    try:
        simple_consumer.startup()
        try:
            simple_consumer.subscribe(topic)
            # use tag filter
            # simple_consumer.subscribe(topic, FilterExpression("tag"))
            while True:
                try:
                    messages = simple_consumer.receive(32, 15)
                    if messages is not None:
                        print(f"{simple_consumer.__str__()} receive {len(messages)} messages.")
                        for msg in messages:
                            simple_consumer.ack(msg)
                            print(f"{simple_consumer.__str__()} ack message:[{msg.message_id}].")
                except Exception as e:
                    print(f"receive or ack message raise exception: {e}")
        except Exception as e:
            print(f"{simple_consumer.__str__()} subscribe topic:{topic} raise exception: {e}")
            simple_consumer.shutdown()
    except Exception as e:
        print(f"{simple_consumer.__str__()} startup raise exception: {e}")
        simple_consumer.shutdown()