from machine import Pin
import time

red = Pin(1, Pin.OUT)
green = Pin(5, Pin.OUT)
yellow = Pin(9, Pin.OUT)

leds = [red, green , yellow]

def traffic_signal():
    for led in leds:
        led.value(1)
        time.sleep(0.8)
        led.value(0)

def blink_all_three():
    for _ in range(3):
        for led in leds:
            led.value(1)
        time.sleep(0.5)
        for led in leds:
            led.value(0)
        time.sleep(0.5)

while True:
    traffic_signal()
    blink_all_three()