Repository navigation
issue with ParamSpec and Callable of Callables #16405
Description
Bug Report
When using ParamSpec and passing a Callable that takes a Callable, mypy 1.6.0, 1.6.1 and master rejects the input, this is a regression from 1.5.1
To Reproduce
from typing import *
T_Retval = TypeVar("T_Retval")
P = ParamSpec("P")
def run(
func: Callable[[], T_Retval],
*args: object,
backend: str = "asyncio",
) -> T_Retval:
return func()
def run_portal():
pass
def submit(
func: Callable[P, T_Retval],
/,
*args: P.args,
**kwargs: P.kwargs,
) -> T_Retval:
return func(*args, **kwargs)
submit(
run,
run_portal,
backend="asyncio",
)https://mypy-play.net/?mypy=1.6.1&python=3.11&gist=e282d121f479fcb77ec89daeb2a07b60
Expected Behavior
Should pass
Actual Behavior
main.py:29: error: Argument 1 to "submit" has incompatible type "Callable[[Callable[[], T_Retval], VarArg(object), DefaultNamedArg(str, 'backend')], T_Retval]"; expected "Callable[[Callable[[], Any], str], T_Retval]" [arg-type]
Your Environment
- Mypy version used: 1.5.1 (passes) 1.6.1, 1.6.0, master (fails)
- Mypy command-line flags:
- Mypy configuration options from
mypy.ini(and other config files): - Python version used: 3.11
Activity
ilevkivskyi commentedon Nov 4, 2023
This may be caused by #15896, IIRC. It was kind of an intentional trade-of. We added support for some more common cases (e.g. generic apply with positional arguments) knowing this may cause some regressions for more tricky cases (e.g. those involving keyword-only arguments). The decision was to see what use cases people actually need, and add some special-casing accordingly.
Since this is quite a tricky thing, the fix will not be available in 1.7, even though this is technically a regression (unless I will find a low-risk solution), fix will probably be available in 1.8.
Ignore position if imprecise arguments are matched by name (#16471)
Ignore position if imprecise arguments are matched by name (#16471)