Add support for namespace-packages without __init__.py (PEP420)

In Python 3 modules don’t require an __init__.py anymore, they are referred to as namespace packages then (see PEP 420 for details). It seems that those are not supported by import-linter at the moment, I’m getting Could not find package.initless.module when scanning …. This may be due to a missing __init__.py file in the parent package warnings and Module 'package.initless' does not exist. errors. In my case the structure is roughly:

package
  __init__.py
  initless
    module.py

It would be great if this could be supported.

[seddonym]

I’m pleased to say there is now a PR in place which offers support for namespace packages: https://github.com/seddonym/import-linter/pull/127

@tozka This should now meet your needs. @jstriebel, I have a feeling this won’t exactly fulfil your needs I’m afraid but you might want to take a look just in case.

Comments and testing welcome.

[tozka]

We also use namespace packages. We have separate distribution packages using common root package.

Another benefit: Namespace packages make it easier to develop when you have multiple modules with the asme common prefix e.g I have a project “cool” - with package “companyname.cool” and project “hot” that depends on cool.

While developing cold we would use pip install -e . to install it in editable form and thus companyname.hot would be from local folder while companyname.cool would be from site-packages of python. Without namespace packages only one would be found.

import-linter looked really promising for us but we need namespace packages so we cannot use it.