[jay23606]

Problem

When pa.array() is called without from_pandas, it sets from_pandas=True automatically only for pandas Series and Index inputs. A pandas ExtensionArray such as pd.array([1.2, np.nan], dtype=float) was not detected, so NaN was kept as NaN instead of being converted to null, unlike the Series case.

Change

In get_values (python/pyarrow/array.pxi), the generic branch now sets is_pandas_object when the input has an extension dtype (pandas_api.is_extension_array_dtype(obj)). Plain lists and numpy arrays keep the existing behaviour.

Testing

Added test_pandas_null_sentinels_extension_array in python/pyarrow/tests/test_array.py. It checks that pa.array(pd.array([1.2, np.nan], dtype=float)) equals the from_pandas=True result and has one null. The test could not be run in this environment because pyarrow is not built here, so it is verified by CI only. Only a syntax check was run locally: python -c "import ast,sys; ast.parse(open('python/pyarrow/tests/test_array.py',encoding='utf-8').read()); print('syntax ok')".

Regression test: untested: CONTRIBUTING does not mention tests

Fixes #35721

• GitHub Issue: [Python] Recognize pandas arrays in the array() constructor for the from_pandas argument #35721

[jay23606]

I have read the CLA Document and I hereby sign the CLA

[github-actions]

⚠️ GitHub issue #35721 has been automatically assigned in GitHub to PR creator.

[Copilot]

🟢 Approval recommended

No active review issues are recorded for the change aligning ExtensionArray null handling with Series and Index inputs.

No open issues 🎉

What changed in this PR

This PR addresses GH-35721 by extending pa.array()’s automatic pandas null handling to pandas ExtensionArray inputs, aligning them with Series and Index inputs.

Changes:

• Detects extension dtypes in get_values to enable pandas semantics automatically.
• Adds a regression test checking that a floating-point ExtensionArray converts NaN to null when from_pandas is omitted.

The new test was syntax-checked locally; runtime validation remains pending in CI.

File	Description
python/​pyarrow/​tests/​test_array.py	Adds regression coverage for ExtensionArray null handling.
python/​pyarrow/​array.pxi	Uses extension-dtype detection to select pandas semantics.

_{Review effort: Balanced}