Closed
Description
Bug Report & To Reproduce
False-positive-emitting behaviour of a type-alias of typing.Callable[P, R] vs a callback Protocol[P, R] is inconsistent when
- Comparing with each other;
- In the context of a stand-alone expression vs being in a
typing.TypeVar(bound=...)expression; - When being accessed from a module as opposed to a straight import.
Source module
# my_module.py
import typing as t
P = t.ParamSpec("P")
R = t.TypeVar("R", covariant=True)
CallableAlias = t.Callable[P, R]
class CallableProtocol(t.Protocol[P, R]):
def __call__(self, *args: P.args, **kwargs: P.kwargs) -> R:
...
t.Callable[..., t.Any] # OK
CallableAlias[..., t.Any] # mypy: Type application is only supported for generic classes [misc] \
# mypy: Unexpected "..." [misc]
CallableProtocol[..., t.Any] # OK
C0T = t.TypeVar("C0T", bound=t.Callable[..., t.Any])
C1T = t.TypeVar("C1T", bound=CallableAlias[..., t.Any]) # mypy: Unexpected "..." [misc]
C2T = t.TypeVar("C2T", bound=CallableProtocol[..., t.Any])
# All OK
c0: t.Callable[..., t.Any]
c1: CallableAlias[..., t.Any]
c2: CallableProtocol[..., t.Any]Module importing from source module
import typing as t
import my_module as m
from my_module import CallableAlias, CallableProtocol
t.Callable[..., t.Any] # OK
m.CallableAlias[..., t.Any] # mypy: Type application is only supported for generic classes [misc] \
# mypy: Unexpected "..."
m.CallableProtocol[..., t.Any] # mypy: Unexpected "..." [misc]
CallableAlias[..., t.Any] # mypy: Type application is only supported for generic classes [misc] \
# mypy: Unexpected "..."
CallableProtocol[..., t.Any] # OK
C0T = t.TypeVar("C0T", bound=t.Callable[..., t.Any]) # OK
C1T = t.TypeVar("C1T", bound=m.CallableAlias[..., t.Any]) # mypy: Unexpected "..."
C2T = t.TypeVar("C2T", bound=m.CallableProtocol[..., t.Any]) # mypy: Unexpected "..."
C3T = t.TypeVar("C3T", bound=CallableAlias[..., t.Any]) # mypy: Unexpected "..."
C4T = t.TypeVar("C4T", bound=CallableProtocol[..., t.Any]) # OK
# All OK
c0: t.Callable[..., t.Any]
c1: t.CallableAlias[..., t.Any]
c2: t.CallableProtocol[..., t.Any]
c3: CallableAlias[..., t.Any]
c4: CallableProtocol[..., t.Any]Expected Behavior
No errors emitted by mypy
Your Environment
- Mypy version used:
v1.3.0 - Mypy command-line flags: None
- Mypy configuration options from
mypy.ini(and other config files):[mypy] strict = True warn_unreachable = True enable_error_code = redundant-expr, truthy-bool, ignore-without-code, unused-awaitable disallow_untyped_calls = False warn_unused_configs = True
- Python version used: 3.10