How do I change the screen brightness in windows using python?

Question

How do I change the screen brightness in windows using python, without using any extra python packages? I'd also like a way of getting what the screen brightness is currently at. I'm thinking that will need to be by using ctypes, but I can't find any information on how to do it.

It annoys me the way the screen brightness buttons on windows adjust the screen brightness in very large increments, so I made a python tkinter program to display the current screen brightness on the taskbar and when I scroll the mouse wheel on the tkinter window it changes the screen brightness:

import subprocess
from tkinter import Canvas, Tk

win = Tk()
win.overrideredirect(True)

canvas = Canvas(win, bg = "#101010", highlightthickness = 0)
canvas.pack(fill = "both", expand = True)

def trim(string, l = None, r = None, include = False, flip = False):
    string = str(string)
    if l and l in string:
        string = string[(string.rindex(l) if flip else string.index(l)) + (0 if include else len(l)):]
    if r and r in string:
        string = string[:(string.index(r) if flip else string.rindex(r)) + (len(r) if include else 0)]
    return string

def set_screen_brightness():
    subprocess.run(
        ["powershell",
         f"(Get-WmiObject -Namespace root/WMI -Class WmiMonitorBrightnessMethods).WmiSetBrightness(1,{current_brightness})"],
        stdout = subprocess.PIPE, stderr = subprocess.STDOUT, shell = True)

def get_screen_brightness():
    value = subprocess.check_output(
        ["powershell", f"Get-Ciminstance -Namespace root/WMI -ClassName WmiMonitorBrightness"],
        shell = True)
    return int(trim(value, l = "CurrentBrightness : ", r = r"\r\nInstanceName      : "))

current_brightness = get_screen_brightness()

brightness_text = canvas.create_text(30, 25, text = current_brightness,
                                         font = ("Segue ui", 14, "bold"), fill = "White", anchor = "w")

sw, sh = win.winfo_screenwidth(), win.winfo_screenheight()
win.geometry(f"69x50+{sw - 505}+{sh - 49}")

def mouse_wheel_screen_brightness(scroll):
    global current_brightness, mouse_wheel_screen_brightness_wa
    if "mouse_wheel_screen_brightness_wa" in globals():
        win.after_cancel(mouse_wheel_screen_brightness_wa)

    current_brightness += 2 if scroll else -2
    if current_brightness < 0: current_brightness = 0
    if current_brightness > 100: current_brightness = 100
    canvas.itemconfig(brightness_text, text = current_brightness)

    mouse_wheel_screen_brightness_wa = win.after(100, lambda: set_screen_brightness())

win.bind("<MouseWheel>", lambda e: mouse_wheel_screen_brightness(e.delta > 0))

def topmost():
    win.attributes("-topmost", True)
    win.after(100, topmost)
topmost()

win.mainloop()

I'm sure there must be a fast way of changing the screen brightness in ctypes, without any extra python packages. With using a subprocess call to Powershell the screen brightness text keeps freezing. I want to do it without using any extra python packages because when I try to install a python package it says that there was a problem confirming the ssl certificate. I googled it and tried to fix it, but I can't get it to work.

Vary

Answer 1

Install screen brightness control using pip Windows: pip install screen-brightness-control

Mac/Linux: pip3 install screen-brightness-control I guess

Then use this code

import screen_brightness_control as sbc

sbc.set_brightness(25) # Number will be any number between 0 and hundred
# Sets screen brightness to 25%

I found info on the screen brightness module here

Witting

I said that I want to do it with just using the python standard library. Edited to make it clearer that I want to do it without using any extra python packages. – Vary

Answer 2

I used the WMI library and it really worked fine. Here is the code, but this is for Windows. I think it is OS specific so if it doesn't work for you, you should look for a better solution.

import wmi
    
brightness = 40 # percentage [0-100] For changing thee screen 
c = wmi.WMI(namespace='wmi')
methods = c.WmiMonitorBrightnessMethods()[0]    
methods.WmiSetBrightness(brightness, 0)

Please upvote and accept the answer if you like it.

Static

Please upvote and accept answer if you liked it. – Static

I said that I want to do it without using any extra python packages. – Vary

Answer 3

by the help of PowerShell commands we can easily increase or decrease the brightness of windows without any external packages

WmiSetBrightness(1,<brightness % goes here>)

import subprocess

subprocess.run(["powershell", "(Get-WmiObject -Namespace root/WMI -Class WmiMonitorBrightnessMethods).WmiSetBrightness(1,40)"])

the subprocess is the internal library that comes with python.

just run the above code, hope this will work.

Organize

The problem with this is it is very slow, I'm sure there must be a faster way of doing it using ctypes, without any extra python packages. – Vary

I have edited my question to explain that with a subprocess call to powershell the screen brightness text in a tkinter window keeps freezing. I'm very sorry that I didn't explain what I am doing when I asked this question. – Vary

Answer 4

The another way to do it without any library is:

import subprocess


def run(cmd):
    completed = subprocess.run(["powershell", "-Command", cmd], capture_output=True)
    return completed

if __name__ == '__main__':
    take_brightness = input("Please enter the brightness level: ")
    command = "(Get-WmiObject -Namespace root/WMI -Class WmiMonitorBrightnessMethods).WmiSetBrightness(1," + take_brightness + ")"
    hello_command = f"Write-Host {command}"
    hello_info = run(hello_command)

Static

Did you get the answer? If yes, then please upvote it and accept he answer. – Static

The problem with this is it is very slow, I'm sure there must be a faster way of doing it using ctypes, without any extra python packages. – Vary

I don't think that it is slow. In my case it was working awwsm. – Static

I have edited my question to explain that with a subprocess call to powershell the screen brightness text in a tkinter window keeps freezing. I'm very sorry that I didn't explain what I am doing when I asked this question. – Vary