Python 使用 MQTT
官方参考文档:https://docs.emqx.com/zh/cloud/latest/connect_to_deployments/python_sdk.html
参考文档:https://zhuanlan.zhihu.com/p/187481769
发布消息
首先定义一个 while 循环语句,在循环中我们将设置每秒调用 MQTT 客户端 publish
函数向 /python/mqtt
主题发送消息。
import random import time from paho.mqtt import client as mqtt_client broker = 'broker.emqx.io' port = 1883 topic = "/python/mqtt" # generate client ID with pub prefix randomly client_id = f'python-mqtt-{random.randint(0, 1000)}' 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.on_connect = on_connect client.connect(broker, port) return client def publish(client): msg_count = 0 while True: time.sleep(1) msg = f"messages: {msg_count}" result = client.publish(topic, msg) # result: [0, 1] status = result[0] if status == 0: print(f"Send `{msg}` to topic `{topic}`") else: print(f"Failed to send message to topic {topic}") msg_count += 1 def run(): client = connect_mqtt() client.loop_start() publish(client) if __name__ == '__main__': run()
消息订阅代码
import random from paho.mqtt import client as mqtt_client broker = 'broker.emqx.io' port = 1883 topic = "/python/mqtt" # generate client ID with pub prefix randomly client_id = f'python-mqtt-{random.randint(0, 100)}' 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.on_connect = on_connect client.connect(broker, port) return client def subscribe(client: mqtt_client): def on_message(client, userdata, msg): print(f"Received `{msg.payload.decode()}` from `{msg.topic}` topic") client.subscribe(topic) client.on_message = on_message def run(): client = connect_mqtt() subscribe(client) client.loop_forever() if __name__ == '__main__': run()