Sentry.py

import RPi.GPIO as GPIO
from mfrc522 import SimpleMFRC522
import time
import datetime

relayPin = 4

GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
GPIO.setup(relayPin, GPIO.OUT)
GPIO.output(relayPin,1)

def pin_on(pin):
    GPIO.output(pin,0)

def pin_off(pin):
    GPIO.output(pin,1)

with open("/home/pi/Desktop/id.txt") as file:
    verified = [line.strip() for line in file]
    
rfid= SimpleMFRC522()

print("Sentry started")

try:
    while True:
        cardid = rfid.read_id()
        if str(cardid) in verified:
            now = datetime.datetime.now()
            if(str(cardid)=="???")or (6 > now.weekday() > 4 and 21 > now.hour > 7):
                pin_on(relayPin)
                print(cardid,":",now)
                time.sleep(2)
                pin_off(relayPin)
            else:
                print(cardid, ":Time restricted")
                time.sleep(2)
            
        else:
            print(cardid)
            time.sleep(2)

finally:
    pin_off(relayPin)
    GPIO.cleanup()