Writing everything in one line is a bad practice. It's just bragging about its tricky hardcore solution. It's too bad that many people called this solution "best practice" and "clever". This is a bad practice. And the solution is not smart, but abstruse and overcomplicated.

The solution from fortlasagna is much better. He generally does the same thing. But his code is much better structured and much better readable. Here he really shows the best practice.

it seems he is working for Google and have no time to answer

very cool my boy

whats the bottom line mean

I missed the "All spaces in the string should be retained" part!
Other than that I got it! Wohoo!

when you use if nums

python check if the list at least have one element and return true

if list is empty python return false so automatically the if block is not excuted

nice

yessir

same as what did!

Well, I think that's wrong: the natural incstinct as a programmer is (or should be) to made the code clear and that includes variables that should be readable, consistent vs the code and logical so others (or our future ourselves) will know what the heck was a variable for. Obviously not in a short kata nor in some conditional/bucle sentences but in long programs, right?

This is a great solution for double and single spaces! But for anything more you'll need to utilize RegEx

Yeah, I would like to see that!!!

there's no problem? is there a problem? what is the problem?

and what's the problem if we only accept bool values?

just the zen of python ;)
but the point I was focusing is the build-in filter