What is the type of a Logger function like Logger.info?

How do I type annotate a Logger function like Logger.info? Using reveal_type returns this:

Revealed type is "def (msg: builtins.object, *args: builtins.object, *, exc_info: Union[None, builtins.bool, Tuple[Type[builtins.BaseException], builtins.BaseException, Union[types.TracebackType, None]], Tuple[None, None, None], builtins.BaseException] =, stack_info: builtins.bool =, stacklevel: builtins.int =, extra: Union[typing.Mapping[builtins.str, builtins.object], None] =)"

There must be a more concise type for this, how do I go about finding it?

It depends on how precise you want/need it.

Revealing the type shows you the exact signature of the function. The most accurate annotation would be using a custom tailored callable protocol reflecting that exact function signature.

To shamelessly steal from typeshed:

from collections.abc import Mapping
from logging import getLogger
from types import TracebackType
from typing import Optional, Protocol, Union
from typing_extensions import TypeAlias


_SysExcInfoType: TypeAlias = Union[
    tuple[type[BaseException], BaseException, Optional[TracebackType]],
    tuple[None, None, None],
]
_ExcInfoType: TypeAlias = Union[None, bool, _SysExcInfoType, BaseException]


class LogMethod(Protocol):
    def __call__(
        self,
        msg: object,
        *args: object,
        exc_info: _ExcInfoType = None,
        stack_info: bool = False,
        stacklevel: int = 1,
        extra: Optional[Mapping[str, object]] = None,
    ) -> None:
        ...


log = getLogger(__name__)

x: LogMethod = log.info

This should be compatible with Python 3.8+.

To contrast this with the simplest possible annotation based on collections.abc.Callable, the following of course works too.

from collections.abc import Callable


log = getLogger(__name__)

y: Callable[..., None] = log.info

And there are options in between. Depending on what you want this for.