A flake8 plugin to ban PEP-420 implicit namespace packages.
Python 3.8 to 3.12 supported.
First, install with pip:
python -m pip install flake8-no-pep420
Second, if you define Flake8’s select setting, add the INP prefix to it. Otherwise, the plugin should be active by default.
Linting a Django project? Check out my book Boost Your Django DX which covers Flake8 and many other code quality tools.
Implicit namespace packages are directories of Python files without an __init__.py. They’re valid and importable, but they break many tools, such as:
unittest test discovery (and by extension, Django’s test runner)
Mypy without its –namespace-packages option
In most cases, tools fail silently, which can lead to a false sense of security:
Tests may look legitimate but never run
Code may be untested but not appear in coverage statistics
Types may never be checked
PEP-420’s algorithm is non-trivial which is probably why such tools haven’t (yet) implemented it.
INP001: File is part of an implicit namespace package. Add __init__.py?
flake8-no-pep420 will trigger this on the first line of any file that sits in a directory without an __init__.py file.
Often projects have a few root files not in packages, for which an __init__.py file should not be added. For example, Django projects normally have a manage.py file in the root of their repository. In these cases you can ignore the INP001 error. It’s possible to use # noqa: INP001 to ignore the error in-line, but this isn’t possible if the first line is a shebang, such as in Django’s manage.py. In such cases it’s preferable to use Flake8’s per-file-ignores option, for example in setup.cfg:
[flake8] # ... per-file-ignores = manage.py:
Release history Release notifications | RSS feed
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.
Hashes for flake8_no_pep420-2.7.0-py3-none-any.whl