BharatDeva opened a new pull request, #1528:
URL: https://github.com/apache/datafusion-python/pull/1528

   # Which issue does this PR close?
   
   Closes #1516.
   
   # Rationale for this change
   
   The scalar UDF typing currently binds the callable return type to 
`pyarrow.DataType`. That makes type checkers expect UDF implementations to 
return a data type object, even though scalar UDF callables return Arrow arrays 
containing values of the declared return type.
   
   This shows up with the existing `examples/python-udf.py` pattern, where a 
function annotated as returning `pa.Array` is rejected by mypy.
   
   # What changes are included in this PR?
   
   This PR updates the scalar UDF type hints in 
`python/datafusion/user_defined.py` so that:
   
   - the UDF callable return type is bounded to `pa.Array`
   - `ScalarUDF.__init__` accepts a `pa.Field` for the resolved return field
   - the decorator helper accepts the public `pa.DataType | pa.Field` 
return-field input
   
   Runtime behavior is unchanged.
   
   # Are these changes tested?
   
   Yes. I ran the following local checks:
   
   - `uv tool run [email protected] check --config pyproject.toml 
python/datafusion/user_defined.py examples/python-udf.py`
     - Result: `All checks passed!`
   - `uv tool run [email protected] format --check --config pyproject.toml 
python/datafusion/user_defined.py examples/python-udf.py`
     - Result: `2 files already formatted`
   - `git diff --check`
     - Result: passed with no whitespace errors
   
   # Are there any user-facing changes?
   
   Yes, for static typing only. User-defined scalar functions that return Arrow 
arrays should type-check more accurately. There is no runtime API change.
   
   # LLM-generated code disclosure
   
   This type-hint update was prepared with assistance from OpenAI Codex and 
manually reviewed before submission.
   


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to