[issue41938] concurrent.futures.wait calls len() on an possible iterable

Change by Kaushal Rohit : -- keywords: +patch pull_requests: +21553 stage: -> patch review pull_request: https://github.com/python/cpython/pull/22555 ___ Python tracker ___ __

[issue41938] concurrent.futures.wait calls len() on an possible iterable

New submission from Kaushal Rohit : `fs` argument could be an iterable, and calling len on it would raise an Exception. We are converting `fs` into a set anyways for set difference, and that too twice. we can just put an `fs = set(fs)`. Let me know if we choose to go with that and I will mak