import time
import os
import RPi.GPIO as GPIO


GPIO.setmode(GPIO.BOARD)

pins = [8,10,12,14,18,20,22,24]

for pin in pins:
    GPIO.setup(pin, GPIO.OUT) 
    GPIO.output(pin, GPIO.LOW)
    time.sleep(1)
    GPIO.output(pin, GPIO.HIGH)
GPIO.cleanup