please always use the spoiler flag when discsussing code / solutions, otherwise anyone can see it in the general comments thread

same here

1 small problem: It won't work if str contains parenthesis without a pair

zip is so smart

It could have been done

I feel like a monkey after sumbitting my solution and comparing it to this >_<

just loop over it without using a comp .-.

And it's also eficient since all tests are done only if necessary!

It's better than one-string solution!
It's PEP8 relevance.

Interesting approach.

I am learning a lot just by looking at your solutions. I slowly get an idea of the time and space complexity also ;)

(and moreover, it's O(n) ;) )

Nice way to detect whether the chars of a string are enclosed by parentheses or not.