Cannot import loguru.Writable

[phillipuniverse]

I'm trying to write a simplified type hint for what defines a sink like this:

LoguruSink = Union[TextIO, loguru.Writable, Callable[[loguru.Message], None], logging.Handler]

When I do this, I get the following error:

  File "...myproj/config/logging.py", line 109, in <module>
    LoguruSink = Union[TextIO, loguru.Writable, Callable[[loguru.Message], None], logging.Handler]
AttributeError: module 'loguru' has no attribute 'Writable'

I am doing this because I have a dynamic expression like this to define a sink:

def some_other_sink(message: loguru.Message) -> None:
    ...

default_sink = sys.stdout if settings.is_local_dev else some_other_sink

logger.add(
    default_sink, level=settings.log_level.upper(), format=log_fmt
)

When I lint this with Mypy though, it does not quite see the correct type of default_sink, admittedly a bit of a mypy limitation IMO:

myproj/config/logging.py:129: error: No overload variant of "add" of "Logger"
matches argument types "object", "str", "str", "Dict[str, str]"  [call-overload]
        logger.add(
        ^
myproj/config/logging.py:129: note: Possible overload variants:
myproj/config/logging.py:129: note:     def add(self, sink: Union[TextIO, Writable, Callable[[Message], None], Handler], *, level: Union[str, int] = ..., format: Union[str, Callable[[Record], str]] = ..., filter: Union[str, Callable[[Record], bool], Dict[Optional[str], Union[str, int, bool]], None] = ..., colorize: Optional[bool] = ..., serialize: bool = ..., backtrace: bool = ..., diagnose: bool = ..., enqueue: bool = ..., catch: bool = ...) -> int
myproj/config/logging.py:129: note:     def add(self, sink: Callable[[Message], Awaitable[None]], *, level: Union[str, int] = ..., format: Union[str, Callable[[Record], str]] = ..., filter: Union[str, Callable[[Record], bool], Dict[Optional[str], Union[str, int, bool]], None] = ..., colorize: Optional[bool] = ..., serialize: bool = ..., backtrace: bool = ..., diagnose: bool = ..., enqueue: bool = ..., catch: bool = ..., loop: Optional[AbstractEventLoop] = ...) -> int
myproj/config/logging.py:129: note:     def add(self, sink: Union[str, _PathLike[str]], *, level: Union[str, int] = ..., format: Union[str, Callable[[Record], str]] = ..., filter: Union[str, Callable[[Record], bool], Dict[Optional[str], Union[str, int, bool]], None] = ..., colorize: Optional[bool] = ..., serialize: bool = ..., backtrace: bool = ..., diagnose: bool = ..., enqueue: bool = ..., catch: bool = ..., rotation: Union[str, int, time, timedelta, Callable[[Message, TextIO], bool], None] = ..., retention: Union[str, int, timedelta, Callable[[List[str]], None], None] = ..., compression: Union[str, Callable[[str], None], None] = ..., delay: bool = ..., mode: str = ..., buffering: int = ..., encoding: str = ..., **kwargs: Any) -> int
Found 1 error in 1 file (checked 122 source files)
make: *** [lint] Error 1

But if I type hint default_sink like this, mypy is happy with no errors:

def some_other_sink(message: loguru.Message) -> None:
    ...

default_sink: default_sink: Union[TextIO, Callable[[loguru.Message], None]] = sys.stdout if settings.is_local_dev else some_other_sink

logger.add(
    default_sink, level=settings.log_level.upper(), format=log_fmt
)

Buuuut.... my completionist brain is not happy. So 2 questions:

1. Is there a reason that loguru.Writable is not exposed?
2. If you want to keep loguru.Writable un-importable, would you consider exposing a new Sink type that I could use like loguru.Sink?

FWIW I am already using loguru-mypy.

Thanks for the great library! I have dug in pretty deep to it and appreciate the very intentional design decisions that have been made.

[kornicameister]

@phillipuniverse I don't quite this issue belongs to this repository. loguru does in fact define typings but loguru-mypy is a plugin that tries to validate some runtime intricacies.

I suggest submitting this issue to main repository. I am sure @Delgan will do far better work trying to help you.

[phillipuniverse]

Sorry about this! For some reason I thought I was in that repo!

I'm re-opening there, thanks!

[phillipuniverse]

New issue at Delgan/loguru#515.

[kornicameister]

@phillipuniverse not at all ;-) if there was a misunderstanding you're free to submit a proposal how to improve README.md to make it a bit more obvious.

[phillipuniverse]

if there was a misunderstanding you're free to submit a proposal

Naw we're good, the only proposal would be "make sure that @phillipuniverse's browser is pointing to the repository he intended before he opens an issue" and that doesn't feel like it fits in a README ;)

[kornicameister]

LOL cheers bro ;) have fun ;)