Ability to inspect type hints of live objects using .pyi files

[chadrik]

It would be very useful to be able to inspect the type annotations of live objects whose types are defined in pyi files. Merging type annotation with inspect.getargspec would open up a word of possibilities in python, such as automatic UI generation for functions/classes.

As an experiment, I tried the following (yes I know imp is deprecated):

from typing import get_type_hints

import imp
filepath = '/Users/chad/dev/mypy/typeshed/stdlib/2.7/itertools.pyi'

with open(filepath, 'r') as f:
    mod = imp.load_module('itertools', f, filepath, ('.pyi', 'r', 1))
print(get_type_hints(mod.repeat))

This failed because of the use of @overload in the pyi file. Commenting these out got the test working. So, there's at least two problems to solve:

• make live inspection of stubs reliable
• make typing.get_type_hints or a new utility in mypyautomatically fallback to searching for .pyi files. might be related to Search procedure for inline annotations #1190

[gvanrossum]

Sorry, this just isn't going to happen any time soon. Apart from overload there are other reasons why the code in stubs just isn't importable (e.g. forward references).

Your request also blurs the line between mypy and runtime support.

[pirate]

For anyone reading this issue in 2018 looking for automatic runtime type inference, I found this helpful: https://github.com/dropbox/pyannotate