import RPi.GPIO as GPIO import time GPIO.setmode(GPIO.BCM) leds = [10, 12, 13, 14, 15, 16, 17, 18, 19, 21, 24, 26] for led in leds: GPIO.setup(led, GPIO.OUT) GPIO.output(led, GPIO.HIGH) time.sleep(3) for led in leds: GPIO.output(led, GPIO.LOW) GPIO.cleanup()