在启用client_id认证后

sub.py

from paho.mqtt import client as mqtt_client

broker = '192.168.1.176'
port = 1883
topic = "/python/mqtt"
# generate client ID with pub prefix randomly
client_id = 'mq_ldc'
user = 'mq_ldc'
pwd = '1L2d3c456'


def connect_mqtt() -> mqtt_client:
    def on_connect(client, userdata, flags, rc):
        if rc == 0:
            print("Connected to MQTT Broker!")
        else:
            print("Failed to connect, return code %d\n", rc)

    client = mqtt_client.Client(client_id)
    client.username_pw_set(user, pwd)
    client.on_connect = on_connect
    client.connect(broker, port)
    return client


def subscribe(client: mqtt_client):
    def on_message(client, userdata, msg):
        print("Received {} from {} topic".format(msg.payload.decode(), topic))

    client.subscribe(topic)
    client.on_message = on_message


def run():
    client = connect_mqtt()
    subscribe(client)
    client.loop_forever()


if __name__ == '__main__':
    run()

pub.py

import time

from paho.mqtt import client as mqtt_client

broker = '192.168.1.176'
port = 1883
topic = "/python/mqtt"
# generate client ID with pub prefix randomly
client_id = 'mq_ldcTest'
user = 'mq_ldcTest'
pwd = '1L2d3c456'


def connect_mqtt():
    def on_connect(client, userdata, flags, rc):
        if rc == 0:
            print("Connected to MQTT Broker!")
        else:
            print("Failed to connect, return code %d\n", rc)

    client = mqtt_client.Client(client_id=client_id, clean_session=False)
    client.username_pw_set(user, pwd)
    client.on_connect = on_connect
    client.connect(broker, port)
    return client


def publish(client):
    msg_count = 0
    while True:
        time.sleep(1)
        msg = "messages: {msg_count}".format(msg_count=msg_count)
        result = client.publish(topic, msg)
        # result: [0, 1]
        status = result[0]
        if status == 0:
            print("Send {msg} to topic {topic}".format(msg=msg, topic=topic))
        else:
            print("Failed to send message to topic {topic}".format(topic=topic))
        msg_count += 1


def run():
    client = connect_mqtt()
    client.loop_start()
    publish(client)


if __name__ == '__main__':
    run()