How can I check with Python which Window Manager is running?

Question

I want to check which Window Manager the user is using (like GNOME or KDE etc.). How do I do that?

Answer 1

You can't. There is no central place where a program registers itself to say "hi, I'm the window manager".

For instance, I'm running xmonad. I simply start this by calling xmonad in my ~/.xsession file along with a couple of other programs to have it start when I login. You cannot really detect that.