new_contents: import RPi.GPIO as GPIO
  import time
  
  # tell GPIO to use the Pi's board numbering for pins
  GPIO.setmode(GPIO.BOARD)
  
  redLedPin = 22
  switchPin = 18
  ledOn = False
  prevSwitchPressed = False
  
  # set data direction of LED pin to output
  GPIO.setup(redLedPin, GPIO.OUT)
  GPIO.setup (switchPin, GPIO.IN, pull_up_down=GPIO.PUD_UP)
  
  
  
  def loop():
      curSwitchPressed = GPIO.input(switchPin)
  
      # do nothing if switch state has not changed    
      if curSwitchPressed == prevSwitchPressed:
          return
          
      prevSwitchPressed = curSwitchPressed
      
      if curSwitchPressed:
          if ledOn:
              GPIO.output(redLedPin, GPIO.LOW)
              ledOn = False
          else:
              GPIO.output(redLedPin, GPIO.HIGH)
              ledOn = True
      
      return
  
  #loop until keyboard interrupt
  try:
      while True:
          loop()
  except KeyboardInterrupt:
      pass
      
  GPIO.cleanup()
subject: add light toggle switch