Raspberry Pi Python ValueError吗？

我已经写了一段时间的这个python脚本，我只是遇到了这个错误。我以为我需要释放另一个价值，但我不知道我应该在其中赋予什么价值？任何帮助将不胜感激。

错误

 File "door_controllerTEST_V4_RFID.py", line 101, in <module>
    main()

  File "door_controllerTEST_V4_RFID.py", line 94, in main
    authenticator = RfidFileAuthenticator()

  File "door_controllerTEST_V4_RFID.py", line 73, in __init__
    self.readFile()

  File "door_controllerTEST_V4_RFID.py", line 80, in readFile
    id, tag = line.split(',')

ValueError: need more than 1 value to unpack

脚本

#!/usr/bin/env python3
"""Door Lock: System to control an electric lock"""

import piface.pfio as piface
import piface.pfio as pfio
from time import sleep
pfio.init()

class AuthToken:
    def __init__(self, id, secret):
        self.id=id
        self.secret=secret

class DoorControllerPiFace:
    def send_open_pulse(self):
        piface.digital_write(0,1)
        sleep(5)
        piface.digital_write(0,0)

class RfidInput:
    def getInput(self):
        print "waiting for tag"
        tag = raw_input()
        return AuthToken(None,tag)

class RfidFileAuthenticator:
    filename = "tags.txt"
    tags = dict()
    def __init__(self):
        self.readFile()

    def readFile(self):
        secrets = open(self.filename, 'r')
        print "reading from " + self.filename + " file"
        for line in secrets:
                line = line.rstrip('\n')
                id, tag = line.split(',')
                self.tags[tag] = id

    def check(self,token):
        print "checking if " + token.secret + " is valid"
        if token.secret in self.tags:
            print "tag found belonging to: " + self.tags[token.secret]
            return True
        else: "tag not found"
        print
        return False

def main():
    authInput = RfidInput()
    authenticator = RfidFileAuthenticator()
    doorController = DoorControllerPiFace()

    if(authenticator.check(authInput.getInput())):
        doorController.send_open_pulse()

if __name__ == '__main__':
        main()