from machine import Pin
from time import time

led1 = Pin(4,Pin.OUT)
led2 = Pin(0,Pin.OUT)
led3 = Pin(2,Pin.OUT)

while True:
    led1.value(1)
    led2.value(0)
    led3.value(0)
    print("LED1 is ON")
    time.sleep(1)

    led1.value(0)
    led2.value(1)
    led3.value(0)
    print("LED2 is ON")
    time.sleep(1)

    led1.value(0)
    led2.value(0)
    led3.value(1)
    print("LED3 is ON")
    time.sleep(1)