from machine import Pin
from time import sleep
led1 = Pin(2,Pin.OUT)
led2 = Pin(4,Pin.OUT)

def blink_leds_one_after_other():
    led1.on()
    sleep(2)
    led1.off()
    led2.on()
    sleep(3)
    led2.off()
while True:
    blink_leds_one_after_other()