BUG: Series.any and Series.all for empty or all-null pyarrow-backed dtypes (#51631)

* BUG: ArrowExtensionArray boolean reductions for empty or all null array

* whatsnew

* clarify whatsnew

Author: lukemanley

doc/source/whatsnew/v2.1.0.rst

@@ -200,7 +200,7 @@ Sparse
 
 ExtensionArray
 ^^^^^^^^^^^^^^
--
+- Bug in :meth:`Series.any` and :meth:`Series.all` returning ``NA`` for empty or all null pyarrow-backed data when ``skipna=True`` (:issue:`51624`)
 -
 
 Styler

pandas/core/arrays/arrow/array.py

@@ -1142,6 +1142,10 @@ def pyarrow_meth(data, skip_nulls, **kwargs):
                 # Let ExtensionArray._reduce raise the TypeError
                 return super()._reduce(name, skipna=skipna, **kwargs)
 
+        # GH51624: pyarrow defaults to min_count=1, pandas behavior is min_count=0
+        if name in ["any", "all"] and "min_count" not in kwargs:
+            kwargs["min_count"] = 0
+
         try:
             result = pyarrow_meth(data_to_reduce, skip_nulls=skipna, **kwargs)
         except (AttributeError, NotImplementedError, TypeError) as err:

pandas/tests/extension/test_arrow.py

@@ -2144,3 +2144,15 @@ def test_dt_tz_localize(unit):
         dtype=ArrowDtype(pa.timestamp(unit, "US/Pacific")),
     )
     tm.assert_series_equal(result, expected)
+
+
+@pytest.mark.parametrize("skipna", [True, False])
+def test_boolean_reduce_series_all_null(all_boolean_reductions, skipna):
+    # GH51624
+    ser = pd.Series([None], dtype="float64[pyarrow]")
+    result = getattr(ser, all_boolean_reductions)(skipna=skipna)
+    if skipna:
+        expected = all_boolean_reductions == "all"
+    else:
+        expected = pd.NA
+    assert result is expected