import subprocess
import ast


def is_screen_on():
    screen_is_locked = ast.literal_eval(
        subprocess.check_output(
            [
                '/usr/bin/python',  # system one with Quartz available
                '-sc',
                'import Quartz; ' +
                'print Quartz.CGSessionCopyCurrentDictionary().get("CGSSessionScreenIsLocked", False)'
            ],
            encoding='ascii'))
    return not screen_is_locked


def go_lock_screen():
    pass


def go_wake_screen():
    pass


def go_sleep_mode():
    subprocess.run(['pmset', 'sleepnow'])


is_screen_on()