adding type annotation

[martinResearch]

Thank you for the library.
Unfortunately, having this library not typed prevents mypy from propagating types to do efficient static checks.
Is adding type annotation in the roadmap?
Maybe the stubs in here https://github.com/python/typeshed/tree/main/stdlib/multiprocessing could be reused?

[mmckerns]

No, adding type annotations is not currently in the roadmap. Thanks for the pointer to multiprocessing from typeshed. I'll have to look into whether it's realistic to use that as a base as opposed to the stdlib multiprocessing.

[martinResearch]

To be sure there is no confusion: It seems to me that we cannot really oppose the code in here https://github.com/python/cpython/blob/main/Lib/multiprocessing with the code in here https://github.com/python/typeshed/tree/main/stdlib/multiprocessing. It seems that the first one contains the library implementation and does not have any type annotation while the second contains only the annotations and no implementation.

[mmckerns]

👍 there's no confusion

[Jylpah]

Second vote for type hints. Type hints and mypy make Python programming for more robust since the linter will notice many (most of) issues that would otherwise be runtime errors. But I can image it would be quite an effort to add.

[mcrespoae]

Following up on this issue: Third vote for type hints.

[chdominguez]

As a workaround, you can cast multiprocess as multiprocessing for type annotations during development using the typing module:

if typing.TYPE_CHECKING:
    import multiprocessing as mp
else:
    import multiprocess as mp

or

import multiprocess as mp
if typing.TYPE_CHECKING:
   import multiprocessing
   mp = typing.Cast(multiprocessing, mp)