GH-47123: [Python] Add Enums to PyArrow Types

[rmnskb]

Rationale for this change

Please see Github Issue #47123

What changes are included in this PR?

Added public Type Enums that mimic the original private variable groups used for internal type checking.

Are these changes tested?

Yes. Partly for now.

Are there any user-facing changes?

No, just additional features were added: they will now able to access the underlying types directly via the Type Enums.

• GitHub Issue: [Python] BaseExtensionType doesn't extend ExtensionType #47123

[github-actions]

⚠️ GitHub issue #47123 has been automatically assigned in GitHub to PR creator.

[lidavidm]

Thanks!

[lidavidm]

Actually, run-end-encoded is also missing. As are all the binary types

[AlenkaF]

All the comments have been addressed. One more suggestion I have is that this enum could be added to the docs. For example to the API doc:

https://github.com/apache/arrow/blob/main/docs/source/python/api/datatypes.rst

next to Type Classes or Utility Functions. Maybe even in the User Guide =) https://github.com/apache/arrow/blob/main/docs/source/python/data.rst

[AlenkaF]

ps: the linter error is not connected to the changes in this PR. Not sure if there is an issue open already though.

[raulcd]

ps: the linter error is not connected to the changes in this PR. Not sure if there is an issue open already though.

The linter issue is solved on main, rebasing main should fix it.

[rmnskb]

All the comments have been addressed. One more suggestion I have is that this enum could be added to the docs. For example to the API doc:

https://github.com/apache/arrow/blob/main/docs/source/python/api/datatypes.rst

next to Type Classes or Utility Functions. Maybe even in the User Guide =) https://github.com/apache/arrow/blob/main/docs/source/python/data.rst

Thanks for the suggestion! I've put the docs below the Type Checking like so:

Partly because the functions above come from the same module, and also because I think this is the intended usage that @lidavidm imagined initially.
Please let me know if there's something else I could help with :)

[AlenkaF]

Thank you for all the updates, this looks good to me!
Will merge once David has one final check.

[AlenkaF]

@rmnskb one small issue to fix and then we are good to go! =)

______________________ [doctest] pyarrow.types.TypesEnum _______________________
057 
058     Examples
059     --------
060     >>> import pyarrow as pa
061     >>> from pyarrow.types import TypesEnum
062     >>> int8_field = pa.field('int8_field', pa.int8())
063     >>> int8_field.type.id == TypesEnum.INT8
064     True
065 
066     >>> fixed_size_list = pa.list(pa.uint16(), 3)
UNEXPECTED EXCEPTION: AttributeError("module 'pyarrow' has no attribute 'list'")
Traceback (most recent call last):
  File "/opt/conda/envs/arrow/lib/python3.10/doctest.py", line 1350, in __run
    exec(compile(example.source, filename, "single",
  File "<doctest pyarrow.types.TypesEnum[4]>", line 1, in <module>
AttributeError: module 'pyarrow' has no attribute 'list'. Did you mean: 'list_'?

[rmnskb]

@AlenkaF fixed the typo :)

[AlenkaF]

Thank you @rmnskb !

[conbench-apache-arrow]

After merging your PR, Conbench analyzed the 4 benchmarking runs that have been run so far on merge-commit 2949fe8.

There weren't enough matching historic benchmark results to make a call on whether there were regressions.

The full Conbench report has more details.