out-in.py

#!/usr/bin/env python

import piglow
from time import sleep

piglow.auto_update = True
BRIGHT_MAX = 20
bright = BRIGHT_MAX

for count in range(4):
    for x in range(6):
        arr = [x, x + 6, x + 12]
        piglow.set(arr, bright)
        sleep(0.1)

    bright = 0 if bright == BRIGHT_MAX else BRIGHT_MAX