Feature or enhancement

pathlib._abc.PurePathBase and PathBase have a few slots and methods that facilitate fast path object generation:

• _drv, _root, _tail_cached: roughly, the result of os.path.splitroot() on the path
• _str: the normalized path string
• _make_child_relpath(): used when walking directories
• _from_parsed_parts(): used in parent, parents, with_name(), relative_to()

These carefully-tuned features are useful in pathlib, where speed is important, but much less so in pathlib._abc, where the clarity of the interfaces and interactions should win out.

It should be possible to move them to PurePath, leaving PurePathBase with only _raw_paths and _resolving slots.

This should not affect the behaviour or performance of the public classes in pathlib proper.

Linked PRs

• GH-113528: Move a few misplaced pathlib tests #113527
• GH-113528: Remove a couple of expensive pathlib ABC tests #113534
• GH-113528: Slightly improve pathlib.Path.glob() tests for symlink loop handling #113763
• GH-113528: Split up pathlib tests for invalid basenames. #113776
• GH-113528: pathlib ABC tests: add repr to dummy path classes. #113777
• GH-113528: Deoptimise pathlib._abc.PurePathBase.name #113531
• GH-113528: Deoptimise pathlib._abc.PurePathBase.parent #113530
• GH-113528: Deoptimise pathlib._abc.PurePathBase.relative_to() #113529
• GH-113528: Deoptimise pathlib._abc.PurePathBase.is_absolute() #113820
• GH-113528: Deoptimise pathlib._abc.PathBase._make_child_relpath() #113532
• GH-113528: Deoptimise pathlib._abc.PathBase.resolve() #113782
• GH-113528: Deoptimise pathlib._abc.PurePathBase #113559
• GH-113528: Speed up pathlib ABC tests. #113788
• GH-113528: Deoptimise pathlib._abc.PurePathBase.relative_to() (again) #113882
• GH-113528: Deoptimise pathlib._abc.PurePathBase.parts #113883