import paho.mqtt.client as mqtt

配置信息

product_key = ""
device_name = ""
device_secret = ""
region_id = "cn-shanghai"
topic = "/sys/k13k3tVfCRE/YBXC1/thing/event/property/post"#.format(product_key, device_name)#可能改

client_id = "python_mqtt_client" # MQTT客户端的唯一ID

连接成功回调函数

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

收到消息回调函数

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

创建MQTT客户端

client = mqtt.Client(mqtt.CallbackAPIVersion.VERSION1, client_id)
client.on_connect = on_connect
client.on_message = on_message

设置用户名和密码

client.username_pw_set(device_name + "&" + device_secret)

连接阿里云物联网平台

client.connect(product_key + ".iot-as-mqtt." + region_id + ".aliyuncs.com", 1883, 60)

开始循环监听

client.loop_forever()

总是报这个错：Connected with result code 4