我在我的Raspberry上安装了MQTT代理（Mosquitto），并安装了客户端（Paho Client Python）。我试图启动我的客户端，但我有这个错误时，运行我的文件。

File "client_mqtt.py", line 38, in <module>
    client = mqtt.client()
AttributeError: 'module' object has no attribute 'client'

我的完整档案是

import paho.mqtt.client as mqtt
import sys

#definicoes: 
Broker            = "localhost"
username          = "mosquitto"
password          = "mqtt"
PortaBroker       = 1883
KeepAliveBroker   = 60
client_name       = "Local"

topic_casa = "casa" 
topic_mcu  = "mcu" 

#Callback - conexao ao broker realizada
def on_connect(client, userdata, flags, rc):
    print("[STATUS] Conectado ao Broker. Resultado de conexao: "+str(rc))
    client.subscribe(topic_mcu)
    client.subscribe(topic_casa)
    

#Callback - mensagem recebida do broker
def on_message(client, userdata, msg):
    MensagemRecebida = str(msg.payload)
    
    print("[MSG RECEBIDA] Topico: "+msg.topic+" / Mensagem: "+MensagemRecebida)

def on_disconnect(client, userdata, rc):
    if rc != 0:
        print("Unexpected disconnection.")  

#programa principal:
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.connect(Broker, PortaBroker, KeepAliveBroker)
        client.loop_forever()
except KeyboardInterrupt:
        print "\nCtrl+C pressionado, encerrando aplicacao e saindo..."
        sys.exit(0)