F841 false negative on assignment to multiple variables

[DetachHead]

def foo():
    a = bar() # error: F841
    b, c = bar() # no error

def bar():
    ...

playground

[qdegraaf]

Could this be intentional? From the tests:

def f(tup):
    x, y = tup  # this does NOT trigger F841

Unsure if that was left there as a TODO or consciously omitted. @charliermarsh could you clarify?

[charliermarsh]

Yeah this is intentional for parity with Flake8. I think it's reasonable. An improvement could be to flag x and y if both are unused.

[DetachHead]

I don't get why it should be treated differently. If it's for the case where you only want to use one of the values from the tulle, you can just prefix it with an _ to mark it as intentionally unused:

a, _b = foo()

[zanieb]

Best practice is really

a, _ = foo()

I don't see why we wouldn't raise a violation here, other than flake8 compatibility

[charliermarsh]

I'm not opposed to changing it. I didn't feel strongly so erred towards compatibility.