Toggle between Light & Dark mode.

Toggle macOS Theme.py

#!/usr/bin/python
#
# This toggles the macOS appearance from Light mode to Dark mode and vice
# versa.
#
# Big thanks to Mike Lynn for his help. Esp. this gist:
#   https://gist.github.com/pudquick/ba235b7e90aafb9986158697a457a0d0
#
# Still looking for the function to perfectly simulate changing themes via the
# System Prefs UI. iStat menus seems to not be getting the hint.

import platform
from Foundation import NSBundle

vers, _, _ = platform.mac_ver()
if float(vers.split('.')[1]) != 14:
    exit
else:
    appearanceBundle = NSBundle.bundleWithPath_("/System/Library/PreferencePanes/Appearance.prefPane")
    appearanceShared = appearanceBundle.classNamed_('AppearanceShared')
    app = appearanceShared.sharedAppearanceAccess()
    if app.theme() == 1:
        app.setTheme_(0)
    else:
        app.setTheme_(1)

Doesn't notify apps when run from a different user context. Even sudo -u "$username from the root user doesn't send the notification to apps.
Yeah. This is a decent start, but needs some fluff for EUX.