The game of SET in a solitaire version using python3 and tkinter. The ZIP files contain images for the 81 cards in the game (big for each hand, small to keep track of sets picked).
I can't take full credit for all the code here - a friend had written a working version of the basic framework in Perl quite a while ago, and I "re-purposed" it as a Python programming exercise. I'm a bit of a hack as a coder - and still don't quite grasp the concepts of OOP programming, but porting her code gave me something tangible and much more fun to learn with than the following typical python tutorials - although I did make frequent use of YouTube videos on python too.
The game works on most platforms I've tested, but the Mac version has some deficiencies with the "hint" function, and it hung on a newer ubuntu box when updating the screen after solving for all SETS. Anyway, it's a fun way to kill some time if you're sitting in front of a PC waiting for some other task to complete. I usually find all SETS in 20-30 minutes with no hints, but the reason there's a hint button is because some boards can seem impossible - and are best solved by coming back to it later..