ProcessPoolExecutor initializer 3.11 overloads return object?

[davetapley]

The docs say:

initializer is an optional callable that is called at the start of each worker process;

No mention of it returning anything.

And type is Callable[..., None] as expected:

typeshed/stdlib/concurrent/futures/process.pyi

Lines 157 to 159 in 5eb040b

	class ProcessPoolExecutor(Executor):
	_mp_context: BaseContext | None
	_initializer: Callable[..., None] | None

But then for >=3.11 there's this overload:

typeshed/stdlib/concurrent/futures/process.pyi

Lines 173 to 179 in 5eb040b

	if sys.version_info >= (3, 11):
	@overload
	def __init__(
	self,
	max_workers: int | None = None,
	mp_context: BaseContext | None = None,
	initializer: Callable[[], object] | None = None,

---

Seems to have come in on 8b3b6bf.
@AlexWaygood am I missing something? 🤔

[hauntsaninja]

We should update the instance variable. Every Callable[..., None] is a Callable[[], object]. ProcessPoolExecutor just ignores whatever is returned, so it's valid to pass something into it that happens to return a value. Typeshed typically prefers false negatives over false positives.

See also the discussion in PyCQA/flake8-pyi#237 (comment)

[davetapley]

Oh, TIL isinstance(None, object), I guess that should have been obvious 🤪

We should update the instance variable.

I'm not sure what variable you mean? 🤔