Kata says function "takes a list of non-negative integers and strings"

it should be non-negative...

Thanks, I must not have noticed this :)

"a list of non-negative integers and strings" states clearly that this list can only contain non-negative integers or strings, nothing else :)

What if one of the elements is a float or boolean?

that ; is disturbing :D

Ut oh a ; found it's way into our beautiful Python code :o

I tend to use itemgetter because it's cleaner code than the lambda.

I'm happy with either solution. In most cases, I'd probably just use the lambda rather than itemgetter unless I knew I'd be working with a large dataset, but either way works fine. itemgetter turns out to be a little bit less expensive, time wise, and you only have to pay the import cost once, so I decided to run with that instead of the lambda.

itemgetter is always such a dilemma for it.
I like how clean and nice it is, but I almost never
use it because adding a whole import just for it feels silly,
especially since lambda x: x[n] is just as long anyway.

Okay, I'm closing this issue now.

@Sebbe The author wrote this elsewhere, which I think answers your question:

"In Javascript/Coffeescript, you will need to use a nested Array.

In Python, you can use nested lists, nested sets, generators of generators, I wrote it to be pretty flexible."

Please close this issue.