Why? Efficiency?

mmmm... I kind of feel it's about spot on in comparison to some other 5kyu kata's I've done. I like them like this when the challenge is more about the algorithm and code, rather than deciphering what is being asked for.

Yes but we are doing python 3. sorry. Floor division WINS!

No, there is no such mistake in the tests. You probably carry over some state from one solution to another.

Closing as not a kata issue.

I just solved the kata and checked: in tests, it's [7,9], so example of [7,8] is a mistake.
When you solve this kata, remeber to try its harder version! Closest pair of points in linearithmic time

No, that will invalidate everything. Plus it's only a white kata...

To each their own.
When there is only one thing to add to a string, either at the beginning or the end, this can look clearer this way.
(I used an f-string though)

Nobody's going to change the requirements after 2500+ solutions were submitted.

because this solution is supposed to be run with python 2. Replace string with str (and only then, the import isn't needed...)

I am using python 3.7.3, having a "name 'string' is not defined" error when string was not imported. Any idea? pls.

That should be a question, not an issue: you keep removing by 3 and it should work.

Not a suggestion.