Python MQTT客户端连接服务器订阅和发布

import paho.mqtt.client as mqtt
broker_url: str = "192.168.2.13" #MQTT服务器IP
broker_port: int = 1883
client = mqtt.Client()
client.username_pw_set(username="ubuntu", password="ubuntu") #MQTT服务器用户名与密码

def on_subscribe(client, userdata, mid, granted_qos):
        print("订阅成功")

def on_connect(client, userdata, flags, rc):
        print("连接成功")
        #订阅python消息
        client.subscribe(topic="python", qos=0) 

def on_message(client, userdata, msg):
        print("消息到来")
        print(msg.topic + "" + str(msg.payload))

if __name__ == '__main__':
        client.on_connect = on_connect
        client.on_subscribe = on_subscribe
        client.on_message = on_message
        client.connect(host=broker_url, port=broker_port)
        client.loop_start()
        # client.loop_forever() 可与 client.loop_start()
        # 发布python消息数据
        client.publish(topic="python", payload="数据", qos=0, retain=False)