https://github.com/ariebovenberg/slotscheck

🎰 Ensure your __slots__ are working properly
https://github.com/ariebovenberg/slotscheck

Last synced: 7 days ago
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🎰 Ensure your __slots__ are working properly

• Host: GitHub
• URL: https://github.com/ariebovenberg/slotscheck
• Owner: ariebovenberg
• License: mit
• Created: 2021-12-29T16:56:38.000Z (about 3 years ago)
• Default Branch: main
• Last Pushed: 2024-04-08T10:56:02.000Z (9 months ago)
• Last Synced: 2024-04-08T11:50:54.308Z (9 months ago)
• Language: Python
• Homepage: https://slotscheck.rtfd.io
• Size: 617 KB
• Stars: 85
• Watchers: 4
• Forks: 8
• Open Issues: 16
• Metadata Files:
  • Readme: README.rst
  • Changelog: CHANGELOG.rst
  • License: LICENSE

Awesome Lists containing this project

• awesome-python-testing - slotscheck - Find mistakes in your `__slots__` definitions. (Static Checks)

README

        
🎰 Slotscheck

=============

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Adding ``__slots__`` to a class in Python is a great way to improve performance.

But to work properly, all base classes need to implement it — without overlap!

It's easy to get wrong, and what's worse: there is nothing warning you that you messed up.

✨ *Until now!* ✨

``slotscheck`` helps you validate your slots are working properly.

You can even use it to enforce the use of slots across (parts of) your codebase.

See my `blog post `_

for the origin story behind ``slotscheck``.

Quickstart

----------

Usage is quick from the command line:

.. code-block:: bash

   python -m slotscheck [FILES]...

   # or

   slotscheck -m [MODULES]...

For example:

.. code-block:: bash

   $ slotscheck -m sanic

   ERROR: 'sanic.app:Sanic' defines overlapping slots.

   ERROR: 'sanic.response:HTTPResponse' has slots but superclass does not.

   Oh no, found some problems!

   Scanned 72 module(s), 111 class(es).

Now get to fixing —

and add ``slotscheck`` to your CI pipeline or

`pre-commit `_

to prevent mistakes from creeping in again!

See `here `__ and

`here `__ for examples.

Features

--------

- Detect broken slots inheritance

- Detect overlapping slots

- Detect duplicate slots

- `Pre-commit `_ hook

- (Optionally) enforce the use of slots

See `the documentation `_ for more details

and configuration options.

Why not a flake8 plugin?

------------------------

Flake8 plugins need to work without running the code.

Many libraries use conditional imports, star imports, re-exports,

and define slots with decorators or metaclasses.

This all but requires running the code to determine the slots and class tree.

There's `an issue `_

to discuss the matter.

Notes

-----

- ``slotscheck`` will try to import all submodules of the given package.

  If there are scripts without ``if __name__ == "__main__":`` blocks,

  they may be executed.

- Even in the case that slots are not inherited properly,

  there may still be an advantage to using them

  (i.e. attribute access speed and *some* memory savings).

  However, in most cases this is unintentional.

  ``slotscheck`` allows you to ignore specific cases.

- Because ``slotscheck`` imports your code in arbitrary order,

  it can—in rare cases—result in confusing and randomly-occurring import errors

  in third-party libraries.

  In such a case, it is recommended to omit modules such as your tests

  and mypy plugins from the slotscheck run.

  See `here `_.

  Alternatively, you can use ``PYTHONHASHSEED=`` to make the import order deterministic.

  A solution to this problem is being worked on in `this issue `_.

Installation

------------

It's available on PyPI.

.. code-block:: bash

  pip install slotscheck