from machine import Pin
from utime import sleep
red = Pin(1,Pin.OUT)
yellow = Pin(6,Pin.OUT)
green = Pin(10,Pin.OUT)
while(True):
 red.high()
 sleep(20)
 red.low()
 yellow.high()
 sleep(2)
 yellow.low()
 green.high()
 sleep(10)
 green.low()
 yellow.high()
 sleep(2)
 yellow.low()