slotscheck 0.0.1

Check the usage of __slots__.

Adding __slots__ to a class in Python is a great way to reduce memory usage. But to work properly, all subclasses need to implement it. It turns out it’s easy to forget one class in complex inheritance trees. What’s worse: there is nothing warning you that you messed up.

Until now!

Quickstart

Usage is quick from the command line:

slotscheck [MODULE]

For example:

$ slotscheck pandas
incomplete slots in 'pandas.core.internals.blocks.Block'
incomplete slots in 'pandas.core.internals.blocks.NumericBlock'
incomplete slots in 'pandas.core.internals.blocks.ObjectBlock'
incomplete slots in 'pandas.core.internals.array_manager.SingleArrayManager'
incomplete slots in 'pandas.core.internals.managers.SingleBlockManager'
incomplete slots in 'pandas.core.internals.array_manager.BaseArrayManager'
incomplete slots in 'pandas.core.internals.array_manager.SingleArrayManager'
incomplete slots in 'pandas.core.internals.blocks.Block'
incomplete slots in 'pandas.core.internals.blocks.CategoricalBlock'
incomplete slots in 'pandas.core.internals.blocks.DatetimeLikeBlock'
incomplete slots in 'pandas.core.internals.blocks.NumericBlock'
incomplete slots in 'pandas.core.internals.blocks.ObjectBlock'
incomplete slots in 'pandas.core.internals.managers.BaseBlockManager'
incomplete slots in 'pandas.core.internals.managers.SingleBlockManager'

Limitations

• Even in the case that slots are not inherited properly, there may still an advantage to using them (i.e. attribute access speed and _some_ memory savings)

• Only classes at module-level are checked (i.e. no nested classes)

• In rare cases imports may fail, the module is then skipped. This is logged.

Installation

It’s available on PyPI.

pip install slotscheck