Blink LED on Raspberry Pi

blink.py

# replace /sys/class/leds/led0/trigger with /sys/class/leds/led0 while on Raspberry Pi 2 model B


def read_trigger() -> str:
    with open('/sys/class/leds/led0/trigger', 'r') as trigger:
        return trigger.read()

org_trigger = read_trigger()
def disable_trigger():
    with open('/sys/class/leds/led0/trigger', 'w') as trigger:
        trigger.write('none')

def restore_trigger():
    with open('/sys/class/leds/led0/trigger', 'w') as trigger:
        trigger.write(org_trigger)

def led_on():
    with open('/sys/class/leds/led0/brightness', 'w') as brightness:
        brightness.write('255')
    print('on')
    
def led_off():
    with open('/sys/class/leds/led0/brightness', 'w') as brightness:
        brightness.write('0')
    print('off')
    
import time
        
def blink(sec: int):
    disable_trigger()
    for i in range(sec):
        led_on()        
        time.sleep(1)
        led_off()        
        time.sleep(1)

if __name__ == '__main__':
    blink(555555)