import RPi.GPIO as GPIO
from time import sleep
import os
from subprocess import check_output

GPIO.setmode(GPIO.BCM)
GPIO.setup(21, GPIO.IN, pull_up_down=GPIO.PUD_UP)
status = 0

while True:
    input_state = GPIO.input(21)
       if input_state == False:
        if status == 0:
        print('AV')
        status = 1
        #Switch to AV
        os.system("sudo killall emulationstation; tvservice -c \"PAL 4:3\"; fbset -depth 8; fbset -depth 16; emulationstation")
       else:
        print('HDMI')
        status = 0
        #Switch to HDMI
        os.system("sudo killall emulationstation; tvservice -p; fbset -depth 8; fbset -depth 16; emulationstation")
       time.sleep(0.2)
RAW Paste Data

import RPi.GPIO as GPIO
from time import sleep
import os
from subprocess import check_output

GPIO.setmode(GPIO.BCM)
GPIO.setup(21, GPIO.IN, pull_up_down=GPIO.PUD_UP)
status = 0

while True:
    input_state = GPIO.input(21)
    if input_state == False:
        if status == 0:
            print('AV')
            status = 1
            #Switch to AV
            os.system("sudo killall emulationstation; tvservice -c \"PAL 4:3\"; fbset -depth 8; fbset -depth 16; emulationstation")
    else:
        print('HDMI')
        status = 0
        #Switch to HDMI
        os.system("sudo killall emulationstation; tvservice -p; fbset -depth 8; fbset -depth 16; emulationstation")
        time.sleep(0.2)