from utime import sleep
sleep(0.3)

from machine import Pin
led=Pin(21,Pin.OUT)
button=Pin(15,Pin.IN,Pin.PULL_UP)
while 1:
    stat=button.value() #read button value
    if stat==0:
        led.value(1) # on led
        print("led is on")
    else:
        led.value(0) # off led
        print("led is off")
    sleep(0.3)