from machine import Pin
import time

red = Pin(18, Pin.OUT)
green = Pin(8, Pin.OUT)
yellow = Pin(11, Pin.OUT)

while True:
    # Red light
    red.on()
    print("Red Light On")
    time.sleep(0.2)
    red.off()

    # Green Light
    green.on()
    print("Yellow Light On")
    time.sleep(0.2)bbb
    green.off()

    #Yellow light
    red.off()
    yellow.on() 
    print("Green Light On") 
    time.sleep(0.2)
    yellow.off()