Change Windows 10 background in Python 3

Question

I've been trying to find the best way to change the Windows 10 Desktop wallpaper through a python script. When I try to run this script, the desktop background turns to a solid black color.

import ctypes

path = 'C:\\Users\\Patrick\\Desktop\\0200200220.jpg'

def changeBG(path):
    SPI_SETDESKWALLPAPER = 20
    ctypes.windll.user32.SystemParametersInfoA(20, 0, path, 3)
    return;

changeBG(path)

What can I do to fix this? I'm using python3

Answer 1

For 64 bit windows, use:

ctypes.windll.user32.SystemParametersInfoW

for 32 bit windows, use:

ctypes.windll.user32.SystemParametersInfoA

If you use the wrong one, you will get a black screen. You can find out which version your using in Control Panel -> System and Security -> System.

You could also make your script choose the correct one:

import struct
import ctypes

PATH = 'C:\\Users\\Patrick\\Desktop\\0200200220.jpg'
SPI_SETDESKWALLPAPER = 20

def is_64bit_windows():
    """Check if 64 bit Windows OS"""
    return struct.calcsize('P') * 8 == 64

def changeBG(path):
    """Change background depending on bit size"""
    if is_64bit_windows():
        ctypes.windll.user32.SystemParametersInfoW(SPI_SETDESKWALLPAPER, 0, PATH, 3)
    else:
        ctypes.windll.user32.SystemParametersInfoA(SPI_SETDESKWALLPAPER, 0, PATH, 3)

changeBG(PATH)

Update:

I've made an oversight with the above. As @Mark Tolonen demonstrated in the comments, it depends on ANSI and UNICODE path strings, not the OS type.

If you use the byte strings paths, such as b'C:\\Users\\Patrick\\Desktop\\0200200220.jpg', use:

ctypes.windll.user32.SystemParametersInfoA

Otherwise you can use this for normal unicode paths:

ctypes.windll.user32.SystemParametersInfoW

This is also highlighted better with argtypes in @Mark Tolonen's answer, and this other answer.