Check for programs that are in full screen mode

[Joe Aspelund]

I am relatively new to python but still know a few things. I am in the
attempt to write a program that causes a window to pop-up. But I do
not what this to happen if the user is in a program that uses the full
screen such as a game. If anyone knows if in python or another
language I can use that can determine this. I appreciate any help I
can get.