beauty indeed

I also dont understand it

When a string is passed to a boolean evaluation, the empty string '' returns False. Any non-empty string returns True. So "not string" is True if the string is non-empty, False if empty.

What "return not string" mean?

Yeah, this thing is like o(n^2), how does this thing have any best practice votes for it?

time complexity is just awful... ;o

This is a really slick solution. Not only is it readable (for me anyways) its also very short. 10/10

Really very elegant solution.

hehe thats funny, not the best in terms of complexity i think, but still clever:)

Ah yes, I see it now. Very elegant method.

I need to remove all non-parentheses characters for this: string.replace("()", "")

Oh right, the return not string line only works if the string contained only parens at the start. Nice!

Why do you need the first line of the function definition here? Would this solution not work without first creating a string of only parens? Is it an efficiency thing perhaps?