Fascinating, the task was supposed to be straightforward and a way to judge code quality etc. Yet, when the candidate solved it in a simple way, they were told they had a bug that they didn't have. This is okay of course, coding is hard. It could have been an interesting opportunity for discussion, I guess.

What's interesting to me is the conclusion that it's somehow Python's fault. I wonder if that attitude would work if it came from the candidate.

I think we should be more careful with tests like this. They need to be done with more humility, so it's great that the post was written!