[WIP] add stubs for typing

[blueyed]

This is meant to be used for pytest, which mainly uses py.path.local, and is very much work in progress.

/cc @bluetech

[blueyed]

btw: https://github.com/davidfritzsche/pytest-mypy-testing/ might be interesting for testing the stubs.

[bluetech]

Awesome! Will really help with pytest typing.

I have some general comments below, will follow up with concrete comments.

First, I assume that given py is in maintenance mode, the idea is only to add typing for external use and not for internal/development use. And also that we'll probably never want to integrate the types into the code itself, only pyi files.

Given that, I think that the stubs should only really expose the public API, and not include internal/private details. And also, only importable items (functions, classes, etc.) should be included. Or if we want to expose private items, we should prefix them with _ so it's clear they are only "helpers" for the stubs (this is what typeshed does).

py does some weird things with imports but the __init__.py at least makes it very easy to see what is the public API of the package.

[blueyed]

@bluetech Agree! Most of the internal things is generated via stubgen, I am adjusting it as I find issues - have not really checked if I am missing some local changes. It's rather messy still, but when installed helps mypy already.

[bluetech]

BTW, I just checked the pytest code and from the best I can find, these are the imports from py that pytest uses:

py.error.Error

py.iniconfig.IniConfig
py.iniconfig.ParseError

py.io.dupfile
py.io.get_terminal_width
py.io.TerminalWriter

py.path.local

py.xml.escape
py.xml.Namespace
py.xml.raw

Might help direct the focus.

[bluetech]

Most of the internal things is generated via stubgen, I am adjusting it as I find issues - have not really checked if I am missing some local changes.

stubgen is great for this, but I think we should take its output, trim it down and restructure it, as I suggested above, and later also fill up the Anys. WDYT?

(I can help with the effort if you'd like)

[blueyed]

stubgen is great for this, but I think we should take its output, trim it down and restructure it, as I suggested above, and later also fill up the Anys. WDYT?

Sure, of course.

Your help would be appreciated of course. Feel free to go crazy on the branch - hopefully you can push here?

[bluetech]

Your help would be appreciated of course. Feel free to go crazy on the branch - hopefully you can push here?

Great, I can do it now. I'll just send a PR with my suggestions against your repo so you can decide what to do.

[blueyed]

Closing in favor of https://github.com/pytest-dev/py/pull/232.