import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)

GPIO.setup(26, GPIO.IN, pull_up_down = GPIO.PUD_DOWN)

i = 0

while True:
        try:
                GPIO.wait_for_edge(26, GPIO.FALLING)
                i += 1
                str_i = str(i)
                print('luku ' + str_i)

        except:
                print('quit..')
                GPIO.cleanup()

GPIO.cleanup()