PERF: __slots__ not declared consistently, negating some memory savings

[ariebovenberg]

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Reproducible Example

👋 Hello there!

I've found quite some classes declaring __slots__ whose bases classes do not. This negates some of the performance benefits. Fixing this should be a relatively easy performance win.

After some experimentation I've found it's not quite as easy as adding __slots__ = () to the bases classes. But, it should still be relatively simple.

List of affected classes I could find:

pandas.core.internals.array_manager.BaseArrayManager
pandas.core.internals.array_manager.SingleArrayManager
pandas.core.internals.blocks.Block
pandas.core.internals.blocks.CategoricalBlock
pandas.core.internals.blocks.DatetimeLikeBlock
pandas.core.internals.blocks.NumericBlock
pandas.core.internals.blocks.ObjectBlock
pandas.core.internals.managers.BaseBlockManager
pandas.core.internals.managers.SingleBlockManager

Installed Versions

n/a

Prior Performance

No response

[ariebovenberg]

take