A script for adjusting screen brightness in Dell laptops with OLED screens in Ubuntu. It requires xrandr to be installed.

screen-brightness

#!/usr/bin/python3

import logging
import os
import subprocess
import sys
from typing import Literal

logging.basicConfig(level=logging.DEBUG)

FILE_PATH = os.path.join(
    os.path.dirname(os.path.realpath(__file__)), ".screen-brightness"
)


def read_current_level() -> float:
    if not os.path.isfile(FILE_PATH):
        return 1
    with open(
        file=FILE_PATH,
        mode="r",
        encoding="utf-8",
    ) as file:
        current_level = file.readline().strip()
        return float(current_level)


def save_level(level: float) -> None:
    with open(
        file=FILE_PATH,
        mode="w",
        encoding="utf-8",
    ) as file:
        file.write(str(level))


def adjust_level(method: Literal["up", "down"]) -> None:
    adjuster = 0.05 if method == "up" else -0.05
    current_level = read_current_level()
    adjusted_level = current_level + adjuster
    if adjusted_level > 1:
        adjusted_level = 1
    if adjusted_level < 0.2:
        adjusted_level = 0.2
    logging.debug(f"Setting screen brightness to {adjusted_level}.")
    subprocess.run(["xrandr", "--output", "eDP-1", "--brightness", str(adjusted_level)])
    save_level(level=adjusted_level)


if __name__ == "__main__":
    METHOD = sys.argv[1] if len(sys.argv) > 1 else "up"
    adjust_level(method=METHOD)

Is there a reason it stops at 0.2? Is it not safe or something? Since my display is OLED, depending on the lighting values below 0.2 are acceptable, but now I'm wondering if I might screwing up my display or something.

No particular reason, it was a limit I added which suited my needs. It shouldn't break anything allowing it to go to 0.0.