User-defined virtual path objects

[barneygale]

Proposal

Add a PathBase class that can be subclassed by users to implement "virtual paths", e.g. paths within .zip files or on FTP servers, and publish it as an external PyPI package.

Phase 1: Private support in pathlib

• Add private _PathBase class
  • GH-89812: Add pathlib._PathBase #106337
• Merge WalkTests into DummyPathTest
  • GH-110109: Simplify pathlib test setup #110308
  • GH-110109: Move tests for pathlib.Path.walk() into main test classes. #110655
• Sort out __hash__(), __eq__, etc - we shouldn't inherit the PurePath implementation
  • GH-110109: Churn pathlib.PurePath methods #112012
  • GH-110109: Add pathlib._PurePathBase #110670
• Simplify/speed up path walking and globbing
  • GH-72904: Add glob.translate() function #106703
• Add from_uri() classmethod
  • GH-107465: Add pathlib.Path.from_uri() classmethod. #107640

Phase 2: Experimental support in PyPI package

• Move ABCs into pathlib._abc
  • GH-110109: Move pathlib ABCs to new pathlib._abc module. #112881
  • GH-110109: Move tests for pathlib ABCs to new module. #112904
• Figure out the default value for pathmod, if any
  • GH-110109: pathlib tests: store base directory as test class attribute #113221
  • GH-110109: pathlib ABCs: do not vary path syntax by host OS. #113219
• Publish PyPI package

Previous Discussion

https://discuss.python.org/t/make-pathlib-extensible/3428

Linked PRs

• GH-110109: Simplify pathlib test setup #110308
• GH-110109: pathlib docs: bring from_uri() and as_uri() together. #110312
• [WIP] GH-110109: Make pathlib extensible #110321
• GH-110109: Speed up pathlib._PathBase.resolve() #110412
• GH-110109: Move tests for pathlib.Path.walk() into main test classes. #110655
• GH-110109: Add pathlib._PurePathBase #110670
• GH-110109: Churn pathlib.PurePath methods #112012
• GH-110109: Fix misplaced tests for pathlib.WindowsPath.owner() and group() #112239
• GH-110109: Test pure functionality of pathlib.Path user subclasses #112242
• GH-110109: Move pathlib ABCs to new pathlib._abc module. #112881
• gh-110109: Fix installed buildbots now pathlib is a package #112901
• GH-110109: Move tests for pathlib ABCs to new module. #112904
• GH-110109: pathlib ABCs: do not vary path syntax by host OS. #113219
• GH-110109: pathlib tests: store base directory as test class attribute #113221
• GH-110109: Drop use of new regex features in pathlib._abc. #113292
• GH-110109: Fix misleading pathlib._abc.PurePathBase repr #113376
• GH-110109: Adjust test_pathlib_abc imports to ease backporting #113411
• GH-110109: pathlib ABCs: drop use of io.text_encoding() #113417
• GH-110109: pathlib ABCs: drop use of warnings._deprecated() #113419