Backport PR #54591 on branch 2.1.x (Implement any and all for pyarrow numpy strings) (#54796)

Author: phofl

pandas/core/arrays/string_arrow.py

@@ -554,3 +554,16 @@ def value_counts(self, dropna: bool = True):
         return Series(
             result._values.to_numpy(), index=result.index, name=result.name, copy=False
         )
+
+    def _reduce(
+        self, name: str, *, skipna: bool = True, keepdims: bool = False, **kwargs
+    ):
+        if name in ["any", "all"]:
+            arr = pc.and_kleene(
+                pc.invert(pc.is_null(self._pa_array)), pc.not_equal(self._pa_array, "")
+            )
+            return ArrowExtensionArray(arr)._reduce(
+                name, skipna=skipna, keepdims=keepdims, **kwargs
+            )
+        else:
+            return super()._reduce(name, skipna=skipna, keepdims=keepdims, **kwargs)

pandas/tests/extension/base/reduce.py

@@ -25,7 +25,7 @@ def check_reduce(self, s, op_name, skipna):
 
         try:
             alt = s.astype("float64")
-        except TypeError:
+        except (TypeError, ValueError):
             # e.g. Interval can't cast, so let's cast to object and do
             #  the reduction pointwise
             alt = s.astype(object)

pandas/tests/extension/test_string.py

@@ -157,6 +157,12 @@ def test_fillna_no_op_returns_copy(self, data):
 
 
 class TestReduce(base.BaseReduceTests):
+    def _supports_reduction(self, ser: pd.Series, op_name: str) -> bool:
+        return (
+            ser.dtype.storage == "pyarrow_numpy"  # type: ignore[union-attr]
+            and op_name in ("any", "all")
+        )
+
     @pytest.mark.parametrize("skipna", [True, False])
     def test_reduce_series_numeric(self, data, all_numeric_reductions, skipna):
         op_name = all_numeric_reductions

pandas/tests/reductions/test_reductions.py

@@ -1078,6 +1078,25 @@ def test_any_all_datetimelike(self):
         assert df.any().all()
         assert not df.all().any()
 
+    def test_any_all_pyarrow_string(self):
+        # GH#54591
+        pytest.importorskip("pyarrow")
+        ser = Series(["", "a"], dtype="string[pyarrow_numpy]")
+        assert ser.any()
+        assert not ser.all()
+
+        ser = Series([None, "a"], dtype="string[pyarrow_numpy]")
+        assert ser.any()
+        assert not ser.all()
+
+        ser = Series([None, ""], dtype="string[pyarrow_numpy]")
+        assert not ser.any()
+        assert not ser.all()
+
+        ser = Series(["a", "b"], dtype="string[pyarrow_numpy]")
+        assert ser.any()
+        assert ser.all()
+
     def test_timedelta64_analytics(self):
         # index min/max
         dti = date_range("2012-1-1", periods=3, freq="D")