使用python实现mqtt的发布和订阅
需要安装的python库
使用python编写程序进行测试MQTT的发布和订阅功能。首先要安装:pip install paho-mqtt
测试发布(pub)
我的MQTT部署在阿里云的服务器上面,所以我在本机上编写了python程序进行测试。
然后在shell里面重新打开一个终端,订阅一个主题为“chat” mosquitto_sub -t chat
在本机上测试远程的MQTT的发布功能就是把自己作为一个发送信息的人,当自己发送信息的时候,所有订阅过该主题(topic)的对象都将收到自己发送的信息。
mqtt_client.py # encoding: utf-8 import paho.mqtt.client as mqtt HOST = "101.200.46.138" PORT = 1883 def test(): client = mqtt.Client() client.connect(HOST, PORT, 60) client.publish("chat","hello liefyuan",2) # 发布一个主题为'chat',内容为‘hello liefyuan'的信息 client.loop_forever() if __name__ == '__main__': test()
发布/订阅测试
# -*- coding: utf-8 -*- import paho.mqtt.client as mqtt MQTTHOST = "101.200.46.138" MQTTPORT = 1883 mqttClient = mqtt.Client() # 连接MQTT服务器 def on_mqtt_connect(): mqttClient.connect(MQTTHOST, MQTTPORT, 60) mqttClient.loop_start() # publish 消息 def on_publish(topic, payload, qos): mqttClient.publish(topic, payload, qos) # 消息处理函数 def on_message_come(lient, userdata, msg): print(msg.topic + " " + ":" + str(msg.payload)) # subscribe 消息 def on_subscribe(): mqttClient.subscribe("/server", 1) mqttClient.on_message = on_message_come # 消息到来处理函数 def main(): on_mqtt_connect() on_publish("/test/server", "Hello Python!", 1) on_subscribe() while True: pass if __name__ == '__main__': main()
注解函数:
client.connect(self, host, port, keepalive, bind_address) client.publish(self, topic, payload, qos, retain) client.subscribe(self, topic, qos)
测试订阅(sub)
在本机上编写程序测试订阅功能,就是让自己的程序作为一个接收者,同一个主题没有发布(pub)信息的时候,就自己一直等候。
# encoding: utf-8 import paho.mqtt.client as mqtt def on_connect(client, userdata, flags, rc): print("Connected with result code "+str(rc)) client.subscribe("chat") def on_message(client, userdata, msg): print(msg.topic+" " + ":" + str(msg.payload)) client = mqtt.Client() client.on_connect = on_connect client.on_message = on_message client.connect("www.liefyuan.top", 1883, 60) client.loop_forever()
总结
以上所述是小编给大家介绍的使用python实现mqtt的发布和订阅,希望对大家有所帮助,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对我们网站的支持!
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