Trivial map/filter/reduce is not a novel kata idea.

No evidence of being a duplicate.
Close the issue.

Nice kata.

There's quite high chance that this might be a duplicate.
(this issue was intended to block approval)

done

Fixing thousands of katas may not be an entirely realistic task, but enforcing the new tools for new content is definitely a good idea. The suggestion above should be converted into an issue.

Well, B4B raised it as an issue, but it was never resolved

Reraising below: new test framework

Ok, reraising as a suggestion

I think it should be rather a suggestion because this kata was created 3 months ago and there are many more katas with similiar issue; we just cant raise issue against them all..

Not using new test framework: link provided by @Blind4Basics somewhere in the discorse of this kata.

already handled, actually.

no answer, all seems fine, closing.

what do you mean? It's already perimeter_sum...

EDIT: if you tried the kata 3 months ago, you got the old version of the trainer, I guess. When I entered it minutes ago, the function name was correct.

Python: Function name in boilerplate should be perimeter_sum.