I went on an interview one time in which the job was not for python, but in which the coding exercise was in python, the assumption being that they wanted to see how you handled something you didn't know.

The interviewer mentioned having another guy in who announced flat out he was not going to do it even though it was explained that you didn't need to know the language to solve the problem.

I of course had some python familiarity, but I still failed because I couldn't remember the name for binary search and that threw me for a loop when the obvious answer I should have gone for in the exercise was 'here we should use binary search'.