Control MacBook screen brightness with arrow keys on Ubuntu.

brightness.py

# -*- coding: utf-8 -*-

# Written by David Heaney on 21 January 2016
# This software is in the public domain.

import curses

stdscr = curses.initscr()
curses.noecho()
curses.cbreak()
stdscr.keypad(1)

brightness = None

with open('/sys/class/backlight/intel_backlight/brightness', 'r') as f:
    brightness = int(f.read())
    f.close()

def main():
    global brightness
    while True:
        stdscr.clear()

        stdscr.addstr(0,2, "^")
        stdscr.addstr(1,(2 if brightness == 0 else 4 - len(str(brightness))), str(brightness))
        stdscr.addstr(2,2, "v")

        stdscr.refresh()

        c = stdscr.getch()

        if c == curses.KEY_UP:
            brightness += 25
            if brightness >= 1388: brightness = 1388

        elif c == curses.KEY_DOWN:
            brightness -= 25
            if brightness <= 0: brightness = 0

        else:
            continue

        with open('/sys/class/backlight/intel_backlight/brightness', 'w') as f:
            f.write(str(brightness))
            f.close()

if __name__ == '__main__':
    try:
        main()
    except KeyboardInterrupt:
        curses.endwin()