Desktop Background Set: GNOME desktop background settings: subprocess.run(), os.listdir(), datetime, gsettings

desktop_bg_set.py

#!/usr/bin/python3
'''Gnome desktop background settings.'''
from subprocess import run
from os import listdir
from datetime import datetime


WALLPAPERS = listdir('/home/foo/Pictures/Wallpapers')
D = {}

for num, file_name in enumerate(WALLPAPERS):
    D[num] = f'/home/foo/Pictures/Wallpapers/{file_name}'

if datetime.now().isocalendar()[1] % 2 == 0:
    WKDAY = D[datetime.now().weekday()]
else:
    WKDAY = D[datetime.now().weekday() + 7]

run(['gsettings', 'set', 'org.gnome.desktop.background', 'picture-options',
     '"wallpaper"'], check=True)
run(['gsettings', 'set', 'org.gnome.desktop.background', 'picture-uri',
     f'file://{WKDAY}'], check=True)

WALLPAPERS lists 14 images for desktop wallpaper in tile mode. So, depending on whether the week number is even or odd will determine which half of the /home/foo/Pictures/Wallpapers directory the current background scheme will come from. Notice how 7 will be added to the weekday value stored in WKDAY if the week number value is odd.