alfred.py

#!/usr/bin/python

import RPi.GPIO as GPIO
import os.path
import os
import click

### SETTINGS ###
PIN_NUMBER = 4
LOCKFILE = '/var/alfred.lock'
ON = GPIO.LOW
OFF = GPIO.HIGH
### SETTINGS ###

GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
GPIO.setup(PIN_NUMBER, GPIO.OUT)

def lock():
	open(LOCKFILE, 'a').close()

def unlock():
	try:
		os.remove(LOCKFILE)
	except Exception as e:
		pass

def locked():
	return os.path.exists(LOCKFILE)

# Commands
@click.group()
def cli():
	pass

@cli.command()
def on(shouldLock = True):
	GPIO.output(PIN_NUMBER, ON)
	click.echo('On!')

	if shouldLock:
		lock()

@cli.command()
def off(shouldLock = True):
	GPIO.output(PIN_NUMBER, OFF)
	click.echo('Off!')

	if shouldLock:
		lock()

@cli.command()
def con():
	if not locked():
		on(False)

@cli.command()
def coff():
	if not locked():
		off(False)

@cli.command()
def reset():
	unlock()

@cli.command()
def status():
	if GPIO.input(PIN_NUMBER) == ON:
		click.echo('Output is on.')
	else:
		click.echo('Output is off.')

if __name__ == '__main__':
	cli()