neszero.py

#!/usr/bin/python

import RPi.GPIO as GPIO
import os, time

GPIO.setmode(GPIO.BCM)
GPIO.setup(4, GPIO.IN, pull_up_down=GPIO.PUD_UP)    #Low Voltage
GPIO.setup(17, GPIO.IN, pull_up_down=GPIO.PUD_UP)   #Momentary power switch
GPIO.setup(22, GPIO.OUT)                            #ON control
GPIO.output(22, GPIO.HIGH)

while True:
  if (GPIO.input(4)):
    time.sleep(0.25)
  else:
    print ("Low Battery! Shutting down...")
    time.sleep(3)
    os.system("sudo shutdown -h now")
  if (GPIO.input(17)):
    time.sleep(3)
    if (GPIO.input(17)):
      print ("Shutting Down...")
      os.system("sudo shutdown -h now")
  else:
    time.sleep(0.25)