from botcore import *
from time import sleep

# Define variables for blink delay and LED number
delay = 0.5
n_led = 0
 
while True:
    leds.user_num(n_led, True)
    sleep(delay)
    leds.user_num(n_led, False)
    sleep(delay)

    n_led = n_led + 1
    if n_led == 8:
        n_led = 0