[Distutils] How do native namespaces work? (And do they play well with setuptools?)

[Alex Grönholm]

What do you mean by "using"? You mean installing them (for which you 
should never use easy_install anyway, btw), or packaging them? The only 
limitation regarding packaging them is that you currently need to 
explicitly list them in your packaging configuration, as find_packages() 
does not yet support namespace packages.


Thomas Nyberg kirjoitti 24.10.2017 klo 16:01:
> Hello,
>
> I previously posted this to python-list as well as reddit:
>
> 	https://mail.python.org/pipermail/python-list/2017-October/726935.html
> 	https://www.reddit.com/r/learnpython/comments/78emwr/how_to_native_namespaces_work_in_python_35/
>
> So far (as pointed out in the reddit link I posted) it seems like maybe
> I can't use native namespaces in conjunction with setuptools and must
> instead use pip. Is this correct?
>
> Here is my original message which contains all the details:
>
> I'm trying to understand native namespaces. I'm currently using python
> 3.5 as packaged in debian 9. I've been following the instructions here:
>
> 	https://packaging.python.org/guides/packaging-namespace-packages/#native-namespace-packages
>
> Those instructions link to the following example:
>
> 	https://github.com/pypa/sample-namespace-packages/tree/master/native
>
> I presume I'm doing something silly, but I can't get that to work. I've
> tried creating a virtual environment as:
>
> --------------------------------------------------
> $ python3 -m venv venv
> $ source venv/bin/activate
> --------------------------------------------------
>
> _Note_: The virtual environment is active, but I'm stripping the (venv)
> off the prompt below to shorten the lines.
>
> And then I've gone into those repo folders and run their setup.py files
> (e.g. for namespace a):
>
> --------------------------------------------------
> $ cd sample-namespace-packages/native/pkg_a/
> $ python3 setup.py install
> --------------------------------------------------
>
> Then if I try to run their sample verification file, things fail:
>
> --------------------------------------------------
> $ cat sample-namespace-packages/verify_packages.py
> from example_pkg import a
> from example_pkg import b
>
> print(a.name)
> print(a.__path__)
> print(b.name)
> print(b.__path__)
> $ python3 sample-namespace-packages/verify_packages.py
> Traceback (most recent call last):
>    File "sample-namespace-packages/verify_packages.py", line 1, in <module>
>      from example_pkg import a
> ImportError: No module named 'example_pkg'
> --------------------------------------------------
>
> Things seem to be installing:
>
> --------------------------------------------------
> $ ls venv/lib/python3.5/site-packages/
> easy-install.pth           pkg_resources
> easy_install.py            pkg_resources-0.0.0.dist-info
> example_pkg_a-1-py3.5.egg  __pycache__
> example_pkg_b-1-py3.5.egg  setuptools
> pip                        setuptools-32.3.1.dist-info
> pip-9.0.1.dist-info
> --------------------------------------------------
>
> Am I missing something totally obvious here? Does anyone here see what
> I'm doing wrong? Thanks for any help!
>
> Cheers,
> Thomas
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