import RPi.GPIO as GPIO
import time

led = 20
in6 = 6

GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
GPIO.setup(led,GPIO.OUT)
GPIO.setup(in6,GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.output(led,GPIO.LOW)

print "CTRL+C = STOP program"

try:
    while True:
        if GPIO.input(in6) == 0:
            GPIO.output(led,GPIO.HIGH)
        else:
            GPIO.output(led,GPIO.LOW)
except KeyboardInterrupt:
    GPIO.cleanup()  # must be executed before program stop