F841 does not have branch analysis

[sk-]

Summary

F841 does not report variables that are unused in certain branches. Below is a short example (playground) showing the issue

def func(x):
    if x:
        io = ""
    else:
        io = "foo"
        print(io)   

This issue was originally reported to pyflakes and closed as duplicate of PyCQA/pyflakes#715.

They mention is unlikely they will implement branch analysis, but ruff already has (I guess) the machinery needed to support this use case.

Version

v0.11.0 (playground)

[MichaReiser]

They mention is unlikely they will implement branch analysis, but ruff already has (I guess) the machinery needed to support this use case.

Actually, Ruff doesn't have the machinery to support this, but we're working on it. But it's going to take a while to get ready for prime time ;)