[Python] type checker broken for `pyarrow.compute` and other sub-modules

[robsdedude]

I think adding a py.typed marker to the package before all public APIs are typed (even just with a whole bunch of Anys) wasn't ideal. Downstream users will now see a bunch of typing errors because type checkers now assume that pyarrow provides type hints that can be relied upon.

In my case, I'm seeing mypy complain about Module has no attribute "count" [attr-defined] where the module in question is pyarrow.compute.

Please consider either removing the marker until type hints are ready or to make sure all public APIs exist (at least as def xyz(*args: Any, **kwargs: Any) -> Any stubs). Or apply the same __getatrr__ placeholder to all modules, not just the top-level module.

Originally posted by @robsdedude in #48618 (comment)

[robsdedude]

Reproducer

1. Create foo.py

   import pyarrow.compute
   
   pyarrow.compute.count(...)

2. Install mypy and pyarrow: pip install pyarrow==24.0.0 mypy==2.1.0
3. Run mypy

   $ mypy foo.py
   foo.py:3: error: Module has no attribute "count"  [attr-defined]
   Found 1 error in 1 file (checked 1 source file)
   

[jorisvandenbossche]

Going to close this as a duplicate of #49831

[robsdedude]

Sorry for the noise :) my search-foo wasn't strong enough to find the other issue 🙌

[jorisvandenbossche]

No problem! It was a good reminder and I marked the other issue as a blocker for the next release, so we at least do the minimum fix if there has been not enough progress on the actual typing by then.