That whitespace is killing me though...

Yet another built-in I learned today!

Came here to say this

Came here to say the same.

Clever, but certainly not best practice. This code is unreadable and unadaptable.

It's essentially just creating a tuple and looping through it.

This Kata is one of the worst. And the auther is clearly a rude individual who likes to fancy themself better than others. Don't pay them any mind.

That's not a very clear wording, and none of the examples confirm this. If you look in the comments, you'll see a lot of confused people that had the same issue. [2, 2, 3][4, 9, 9] example should at least be put into basic test cases, not hidden among other cases, so that you can spend time thinking about the problem and not deciphering the author's intentions.

Very annoying Kata. Read the instructions VERY carefully. Note that some rules are language specific.

That doesn't work since two '(' would cancell out one '}'... instead consider using a dictionary of counts for each. e.g.

if char in '({[': d[char] += 1

if char in '})]': d[char] -= 1

It's 3 times faster than yours and WAY cleaner.