Script to change screenbrightness on a Thinkpad T410

bright.py

#!/usr/bin/python3

import sys

def readFile(path):
	with open(path, 'r', encoding='utf-8') as file:
		return int(file.read())

def writeFile(path, value):
	with open(path, 'w', encoding='utf-8') as file:
		file.write(str(value))

CHANGE = 300
MAXBRIGHTNESS = readFile('/sys/class/backlight/intel_backlight/max_brightness')
CURRENTBRIGHT = readFile('/sys/class/backlight/intel_backlight/brightness')
newBrightness = CURRENTBRIGHT

if '-get' in sys.argv:
	print('Maximum brightness:', MAXBRIGHTNESS)
	print('Current brightness:', CURRENTBRIGHT)

if not '-v' in sys.argv:
	def print(*args):
		pass

if '-inc' in sys.argv:
	newBrightness = min(MAXBRIGHTNESS, CURRENTBRIGHT + CHANGE)

if '-dec' in sys.argv:
	newBrightness = max(0, CURRENTBRIGHT - CHANGE)

if '-set' in sys.argv:
	percent = int(sys.argv[sys.argv.index('-set')+1])
	if percent >= 0:
		if percent > 100:
			percent = 100
	print('Setting to {}%'.format(percent))
	newBrightness = int(MAXBRIGHTNESS * (percent / 100)) 

if newBrightness != CURRENTBRIGHT:
	writeFile('/sys/class/backlight/intel_backlight/brightness', newBrightness)
	print('New brightness:', newBrightness)