我正在使用RFID阅读器来接收消息。我试图通过将它们附加到emptylist = []
来避免重复的消息,如果它们存在于列表中,则不要进一步附加它们。下面是我的代码:如何将唯一的传入消息追加到列表中?
import paho.mqtt.client as mqtt
def on_connect(client, userdata, flags, rc):
print("Connected with result code " + str(rc))
client.subscribe("/whatver/#")
def on_message(client, userdata, msg): # when PUBLISH msg is rcvd frm the server
payloadjson = json.loads(msg.payload.decode('utf-8'))
line = payloadjson["value"].split(',')
epc = line[1]
payload = {'a': epc[11:35], 'b':payloadjson["devicename"], 'c':payloadjson["sensorname"]}
emptylist = []
emptylist.append(payload)
if payload not in emptylist:
emptylist.append(payload)
print (emptylist)
test = mqtt.Client(protocol = mqtt.MQTTv31)
test.connect(host=_host, port=1883, keepalive=60, bind_address="")
test.on_connect = on_connect
test.on_message = on_message
test.loop_forever()
但是我得到如下输出,这表明追加到emptylist
,但被存储到多个分隔的列表。如果RFID阅读器仍在读取相同的标签,它将继续打印相同的输出。即使RFID阅读器读取相同的标签,我也想删除重复的邮件并仅保留一个。
[{'b': 'READERBASIN.3', 'c': 'ANTENNA.2', 'a': '000000000000130000624462'}] # from Tag A
[{'b': 'READERBASIN.3', 'c': 'ANTENNA.2', 'a': 'abcxxx000000130000627000'}] # from Tag B
[{'b': 'READERBASIN.3', 'c': 'ANTENNA.2', 'a': '000000000000130000624462'}] # from Tag A
[{'b': 'READERBASIN.3', 'c': 'ANTENNA.2', 'a': '000000000000130000624462'}] # from Tag A
.
.
.
我该如何解决这个问题?
感谢您的这个伟大的提示! –