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pow float return value is Any in 0.950 #7733
Description
Bug Report
I upgraded to mypy 0.950 today and ran into the following error involving function return types:
To Reproduce
# x.py
def fn(x: float = 8.9) -> float:
return 2 ** x # error: Returning Any from function declared to return "float" [no-any-return]
Expected Behavior
Expected this to pass cleanly.
Actual Behavior
I'm not sure why this now returns Any.
Your Environment
- Mypy version used: 0.950
- Mypy configuration options from
mypy.ini(and other config files): strict = True - Python version used: Python 3.10.0
- Operating system and version: Mac OSX
Activity
TylerYep commentedon Apr 28, 2022
[-]pow float return value is Any?[/-][+]Incompatible return types (Any, object)[/+][-]Incompatible return types (Any, object)[/-][+]Incompatible return types (Any, object) errors in 0.950[/+]AlexWaygood commentedon Apr 28, 2022
Could you open a separate issue about the second thing? It looks like a completely different problem.
Issue number 1 looks like a pretty clear consequence of #7047 (cc. @JelleZijlstra). We might be able to make the types more specific by adding yet another overload to
int.__pow__orfloat.__rpow__. I can create a PR in the morning.[-]Incompatible return types (Any, object) errors in 0.950[/-][+]pow float return value is Any in 0.950[/+]Akuli commentedon Apr 28, 2022
int ** floatcan be a complex number, if the int is negative.But this doesn't happen for
2 ** float, or for any other positive number instead of 2:0 ** floatbehaves a bit surprisingly, and I don't think we should handle it specially in the stubs. In practice, the0is very unlikely to be specified in a way where the type checker can infer its type to beLiteral[0].