Docstring with alternative __module__ name

[pvleuven]

I'm using pybind11 to create private extension modules which are then accompanied by a pure python wrapper with a public name.

Example:

my_ext_mod/
├── __init__.py
├── _my_ext_mod.pyd

In the init.py, I basically reexport the extension module such that all bound c++ objects have __module__ equal to my_ext_mod. This makes the extension module 'transparent' and the user never sees any private _my_ext_mod. Tools like pybnd11-stubgen and Sphinx work perfectly with this, except for one thing, the docstring in pybind11 add the full qualifier so a class in Sphinx is documented as:

class Dummy
     def my_func(self: _my_ext_mod.Dummy)

which is undesirable. It would be great if pybind11 could offer a way to handle this, I'm quite sure the private extension module approach is quite common. Perhaps something like:

PYBIND11_MODULE(_my_ext_mod, mod, my_ext_mod)

which adds an additional attribute like __public_module__ to all exposed attributes which is then used in the docstring generation?

But perhaps there are better and even already existing solutions?