python mqtt 客户端的实现代码实例
这篇文章主要介绍了python mqtt 客户端代码实例,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下
安装paho-mqtt
pip install paho-mqtt -i http://pypi.douban.com/simple --trusted-host pypi.douban.com
python消息收发实现
import paho.mqtt.client as mqtt from multiprocessing import Process import camera_person_num MQTTHOST = "172.19.4.4" MQTTPORT = 1883 mqttClient = mqtt.Client()
# 连接MQTT服务器 def on_mqtt_connect(): mqttClient.connect(MQTTHOST, MQTTPORT, 60) mqttClient.loop_start()
# 消息处理函数
def on_message_come(lient, userdata, msg):
print(msg.topic + ":" + str(msg.payload.decode("utf-8")))
# 消息处理开启多进程
p = Process(target=talk, args=("/camera/person/num/result", msg.payload.decode("utf-8")))
p.start()
# subscribe 消息订阅
def on_subscribe():
mqttClient.subscribe("test", 1) # 主题为"test"
mqttClient.on_message = on_message_come # 消息到来处理函数
# publish 消息发布
def on_publish(topic, msg, qos):
mqttClient.publish(topic, msg, qos);
# 多进程中发布消息需要重新初始化mqttClient
def talk(topic, msg):
cameraPsersonNum = camera_person_num.CameraPsersonNum(msg)
t_max, t_mean = cameraPsersonNum.personNum()
mqttClient = mqtt.Client()
mqttClient.connect(MQTTHOST, MQTTPORT, 60)
mqttClient.loop_start()
mqttClient.publish(topic, '{"max":' + str(t_max) + ',"mean:"' + str(t_mean) + '}', 1)
def main():
on_mqtt_connect()
on_subscribe()
while True:
pass
if __name__ == '__main__':
main()
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