Python快速上手paho-mqtt物联网

import json
import sys

引入mqtt包

import paho.mqtt.client as mqtt

使用独立线程运行

from threading import Thread

建立mqtt连接

def on_connect(client, userdata, flag, rc):

if rc == 0:
    # 连接成功
    print("Connection successful")
elif rc == 1:
    # 协议版本错误
    print("Protocol version error")
elif rc == 2:
    # 无效的客户端标识
    print("Invalid client identity")
elif rc == 3:
    # 服务器无法使用
    print("server unavailable")
elif rc == 4:
    # 错误的用户名或密码
    print("Wrong user name or password")
elif rc == 5:
    # 未经授权
    print("unaccredited")
print("Connect with the result code " + str(rc))
# 订阅频道
# client.subscribe('31765425213673472', qos=2)

当与代理断开连接时调用

def on_disconnect(client, userdata, rc):

#  rc == 0回调被调用以响应disconnect（）调用
# 如果以任何其他值断开连接是意外的，例如可能出现网络错误。
if rc != 0:
    print("Unexpected disconnection %s" % rc)

当收到关于客户订阅的主题的消息时调用。

def on_message(client, userdata, msg):

print(msg.topic + " " + str(msg.payload))
json_msg = json.loads(msg.payload.decode('utf-8'))
# 加入个人逻辑
pass

当使用使用publish()发送的消息已经传输到代理时被调用。

def on_publish(client, obj, mid):

print("on_Publish, mid: " + str(mid))

当代理响应订阅请求时被调用

def on_subscribe(client, userdata, mid, granted_qos):

print("on_Subscribed: " + str(mid) + " " + str(granted_qos))

当代理响应取消订阅请求时调用。

def on_unsubscribe(client, userdata, mid):

print("on_unsubscribe, mid: " + str(mid))

当客户端有日志信息时调用

def on_log(client, obj, level, string):

print("on_Log:" + string)

mqtt订阅启动函数

def mqtt_subscribe():

global client
client.loop_forever()

mqtt发布启动函数

def mqtt_publish(sensor_data, topic='xxxxxxxx', qos=2):

global client
try:
    client.publish(topic=topic, payload=sensor_data, qos=qos)
except KeyboardInterrupt:
    print("EXIT")
    # 这是网络循环的阻塞形式，[金融期货](https://www.gendan5.com/futures/ff.html)直到客户端调用disconnect（）时才会返回。它会自动处理重新连接。
    client.disconnect()
    sys.exit(0)

client = mqtt.Client()

启动函数

def mqtt_run():

# 账号密码验证放到最前面
client.username_pw_set('user', 'user')
# client = mqtt.Client()
# 建立mqtt连接
client.on_connect = on_connect
client.on_subscribe = on_subscribe
client.on_message = on_message
# 当与代理断开连接时调用
client.on_disconnect = on_disconnect
client.on_log = on_log
# 绑定 MQTT 服务器地址
broker_ip = ''
# MQTT服务器的端口号
# client.connect(host=broker_ip, port=1883, keepalive=6000)
client.connect(host=broker_ip, port=1883)
client.reconnect_delay_set(min_delay=1, max_delay=2000)
client.subscribe('xxxxxxxx', qos=0)
# 创建线程去持续接收订阅信息
subscribe_thread = Thread(target=mqtt_subscribe)
subscribe_thread.start()

if name == "__main__":

mqtt_run()