Namespace package not detected if installed in site-packages

[DingXuefeng]

pylint does not respect namespace pacakge. after debugging I found it's because is_namespace function defined in astroid.interpreter._import.util.py returns False if the submodule search location is in STD_AND_EXT_LIB_DIRS.

        if found_spec and found_spec.submodule_search_locations:
            # But immediately return False if we can detect we are in stdlib
            # or external lib (e.g site-packages)
            if any(
                any(location.startswith(lib_dir) for lib_dir in STD_AND_EXT_LIB_DIRS)
                for location in found_spec.submodule_search_locations
            ):
                return False

this is not a valid assumption. PEP 420 does not say this.

We are working on a big project as many teams. Our project lives in a namespace, say myproj. Different groups work on subproject, such as myproj.simulation and myproj.plot and myproj.calculation. These 3 packages are 3 different git repo and can be pip installed separately but they all goes to site-packages/myproj folder as site-packages/myproj/simulation, site-pacakges/myproj/plot etc. the myproj itself is a namespace package.

We have this need and I believe this is compatible with PEP420, but not with astroid.

I suggest remove line 96-102 of astroid/interpreter/_import/util.py.

[Pierre-Sassoulas]

Thank you for looking into it, do you mind opening a pull request for it ?

[jacobtylerwalls]

We can't just do a straight revert of #1756 without having another solution in hand for not recausing pylint-dev/pylint#7365.

[DingXuefeng]

We can't just do a straight revert of #1756 without having another solution in hand for not recausing pylint-dev/pylint#7365.

Thanks, and I get it. It seems it's not easy to fix it. Let me see if I can fix both with a PR.