我正在使用RFID閱讀器來接收消息。我試圖通過將它們附加到emptylist = []
來避免重複的消息,如果它們存在於列表中,則不要進一步附加它們。下面是我的代碼:如何將唯一的傳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()
但是我得到如下輸出,這表明追加到emptylist
,但被存儲到多個分隔的列表。如果RFID閱讀器仍在讀取相同的標籤,它將繼續打印相同的輸出。即使RFID閱讀器讀取相同的標籤,我也想刪除重複的郵件並僅保留一個。
[{'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
.
.
.
我該如何解決這個問題?
感謝您的這個偉大的提示! –