good job sir

This was my approach except i made first_initial and second_initial and then returned f"string with {first_initial}.{second_initial} as i think it makes it more readable for others. But this is pretty readable as well and shorter, smart!

Good idea, using reduce() method

My thoughts exactly, seems nice and safe

Meanwhile, please remember to put a spoiler tag on your comments if they contain code or a discussion of the solution methods, thanks. I have put the flag on your comment already.

here ya go

Super explanation!

I'd say 6kyu is fine. I get it can be a lot more difficult if you're not familiar with recursion yet.

The compare function for this solution returns a boolean, not 1, -1, or 0, which is required for sort to work. So the sort here doesn't actually do anything. I am not sure how it passed the tests.

This is similar to what I originally wanted to do, but I couldn't figure out how to do the double indexes. Now I know!!