I made it so complicated! This solution is awesome!

good idea!

stack.pop() removes the last element from the stack, if all goes "well" the stack should be empty at the end.

very clever solution. Stack would be generally good for solving symmetry-related problem.

After struggling for hours trying to solve this problem and coming up with a solution with long lines of code. I just wanna say bravo. This is clever. I didn't think of it this way

thank you FArekkusu

good idea !
Is it O(n²) complexity or am I wrong ?

good idea, this would reduce the complexity a little

G(old)

of course.

Would this work for a string '(){}[]'?

this is good, I've never thought about resetting index

I think so too, almost. but i think it should be 'if i > 0: i -= 1'.

Thanks a lot for the explanation FArekkusu!