我編寫(xiě)了一個(gè)代碼，可以在同一個(gè) python 文件中進(jìn)行發(fā)布和訂閱。我的目標(biāo)是能夠無(wú)休止地向燈發(fā)送色溫并接收其狀態(tài)（開(kāi)/關(guān)或在線/離線）。但是，當(dāng)我運(yùn)行代碼時(shí)，我可以向燈發(fā)送消息，但我什么也沒(méi)收到（請(qǐng)注意，發(fā)布者和訂閱者分別工作得很好）import paho.mqtt.client as mqttimport sysimport timetopic = "testtopic/3" topic_casa = "testtopic/1"def on_connect(client, userdata, flags, rc):    print("Connection to the broker. Result : "+str(rc))    client.subscribe(topic_casa, qos=1)    client.publish(topic, light.circadianLight())def on_message(client, userdata, msg):    Message = str(msg.payload)    print("[MSG RECEBIDA] Topico: "+msg.topic+" / Mensagem: "+Message)def on_publish(client,userdata,result):     client.publish(topic, light.circadianLight())    time.sleep(10)def on_disconnect(client, userdata, rc):    if rc != 0:        print("Unexpected disconnection.")  try:    print("[STATUS] Inicializando MQTT...")    #inicializa MQTT:    client = mqtt.Client()    client.username_pw_set(username, password)    client.on_connect     = on_connect    client.on_message     = on_message    client.on_disconnect  = on_disconnect    client.on_publish = on_publish #with this callback we won't be able to #receive messages    client.connect(Broker, PortaBroker, KeepAliveBroker)    client.loop_forever()except KeyboardInterrupt:    print ("\nCtrl+C pressionado, encerrando aplicacao e saindo...")    sys.exit(0)