Implementing Publish and Subscription of mqtt using python

Python library that needs to be installed

Use python to write programs to test the publish and subscription capabilities of MQTT. First, install:pip install paho-mqtt

Test release (pub)

My MQTT is deployed on Alibaba Cloud's server, so I wrote a python program on my machine for testing.

Then reopen a terminal in the shell and subscribe to a topic "chat" mosquitto_sub -t chat

The publishing function of testing remote MQTT on this machine is to treat yourself as a sender. When you send the message, all objects that have subscribed to the topic will receive the message they send.

mqtt_client.py
# encoding: utf-8
import  as mqtt
HOST = "101.200.46.138"
PORT = 1883
def test():
  client = ()
  (HOST, PORT, 60)
  ("chat","hello liefyuan",2) # Post a message with the topic 'chat' and the content 'hello liefyuan'  client.loop_forever()
if __name__ == '__main__':
  test()

Publish/Subscribe to test

# -*- coding: utf-8 -*-
import  as mqtt
MQTTHOST = "101.200.46.138"
MQTTPORT = 1883
mqttClient = ()
# Connect to the MQTT serverdef on_mqtt_connect():
  (MQTTHOST, MQTTPORT, 60)
  mqttClient.loop_start()
# publish messagedef on_publish(topic, payload, qos):
  (topic, payload, qos)
# Message processing functiondef on_message_come(lient, userdata, msg):
  print( + " " + ":" + str())
# subscribe messagedef on_subscribe():
  ("/server", 1)
  mqttClient.on_message = on_message_come # Message arrival processing functiondef main():
  on_mqtt_connect()
  on_publish("/test/server", "Hello Python!", 1)
  on_subscribe()
  while True:
    pass
if __name__ == '__main__':
  main()

Annotation function:

(self, host, port, keepalive, bind_address)
(self, topic, payload, qos, retain)
(self, topic, qos)

Test subscription (sub)

Writing a program to test the subscription function on this machine is to let your program be a recipient, and you will wait for it yourself when the same topic has not published (pub) information.

# encoding: utf-8
import  as mqtt
def on_connect(client, userdata, flags, rc):
  print("Connected with result code "+str(rc))
  ("chat")
def on_message(client, userdata, msg):
  print(+" " + ":" + str())
client = ()
client.on_connect = on_connect
client.on_message = on_message
("", 1883, 60)
client.loop_forever()

Summarize

The above is what the editor introduced to you to use python to implement mqtt's publication and subscription. I hope it will be helpful to everyone. If you have any questions, please leave me a message and the editor will reply to everyone in time. Thank you very much for your support for my website!
If you think this article is helpful to you, please reprint it. Please indicate the source, thank you!