Python下使用mqtt协议_python mqtt模块

一、安装mqtt模块

• pip install paho-mqtt

二、python文件中引入mqtt模块

• import paho.mqtt.client as mqtt

三、创建on_connect、on_message函数

def on_connect(client,userdata,flags,rc):
    print("Connected with result code"+str(rc))
    
def on_message(client,userdata,msg):
    print(msg.topic+" " + ":"+str(msg.payload))
1
2
3
4
5

四、创建一个客户端对象

• client = mqtt.Client()

五、最终程序

import paho.mqtt.client as mqtt

def on_connect(client,userdata,flags,rc):
    print("Connected with result code"+str(rc))

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

client = mqtt.Client()

#当连接时调用on_connect函数
client.on_connect = on_connect
#当接到推送时调用on_message函数
client.on_message = on_message
#设置用户名和密码
client.username_pw_set("wtf","lol")
#设置连接地址和端口还有timeout
client.connect("127.0.0.1",1883,60)
#设置订阅主题
client.subscribe("emq")
#publish方法，第一个参数是d主题，另一个是消息内容
client.publish("emq","hello world",2)
#设置一个循环  当接收到待推送消息时立马调用on_message函数打印
client.loop_forever()

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25