BUG: is_numeric_dtype(ArrowDtype[numeric]) not returning True (#50572)

* BUG: is_numeric_dtype(ArrowDtype[numeric]) not returning True

* Adjust decimal type to be numeric

* Some arrow tests now working

Author: mroeschke

doc/source/whatsnew/v2.0.0.rst

@@ -989,6 +989,7 @@ ExtensionArray
 - Bug in :meth:`Series.round` for pyarrow-backed dtypes raising ``AttributeError`` (:issue:`50437`)
 - Bug when concatenating an empty DataFrame with an ExtensionDtype to another DataFrame with the same ExtensionDtype, the resulting dtype turned into object (:issue:`48510`)
 - Bug in :meth:`array.PandasArray.to_numpy` raising with ``NA`` value when ``na_value`` is specified (:issue:`40638`)
+- Bug in :meth:`api.types.is_numeric_dtype` where a custom :class:`ExtensionDtype` would not return ``True`` if ``_is_numeric`` returned ``True`` (:issue:`50563`)
 
 Styler
 ^^^^^^

pandas/core/dtypes/common.py

@@ -1200,6 +1200,8 @@ def is_numeric_dtype(arr_or_dtype) -> bool:
     """
     return _is_dtype_type(
         arr_or_dtype, classes_and_not_datetimelike(np.number, np.bool_)
+    ) or _is_dtype(
+        arr_or_dtype, lambda typ: isinstance(typ, ExtensionDtype) and typ._is_numeric
     )
 
 

pandas/tests/dtypes/test_common.py

@@ -556,6 +556,24 @@ def test_is_numeric_dtype():
     assert com.is_numeric_dtype(pd.Series([1, 2]))
     assert com.is_numeric_dtype(pd.Index([1, 2.0]))
 
+    class MyNumericDType(ExtensionDtype):
+        @property
+        def type(self):
+            return str
+
+        @property
+        def name(self):
+            raise NotImplementedError
+
+        @classmethod
+        def construct_array_type(cls):
+            raise NotImplementedError
+
+        def _is_numeric(self) -> bool:
+            return True
+
+    assert com.is_numeric_dtype(MyNumericDType())
+
 
 def test_is_float_dtype():
     assert not com.is_float_dtype(str)

pandas/tests/extension/test_arrow.py

@@ -37,7 +37,10 @@
 
 import pandas as pd
 import pandas._testing as tm
-from pandas.api.types import is_bool_dtype
+from pandas.api.types import (
+    is_bool_dtype,
+    is_numeric_dtype,
+)
 from pandas.tests.extension import base
 
 pa = pytest.importorskip("pyarrow", minversion="1.0.1")
@@ -550,16 +553,6 @@ def test_groupby_extension_apply(
         ):
             super().test_groupby_extension_apply(data_for_grouping, groupby_apply_op)
 
-    def test_in_numeric_groupby(self, data_for_grouping, request):
-        pa_dtype = data_for_grouping.dtype.pyarrow_dtype
-        if pa.types.is_integer(pa_dtype) or pa.types.is_floating(pa_dtype):
-            request.node.add_marker(
-                pytest.mark.xfail(
-                    reason="ArrowExtensionArray doesn't support .sum() yet.",
-                )
-            )
-        super().test_in_numeric_groupby(data_for_grouping)
-
     @pytest.mark.parametrize("as_index", [True, False])
     def test_groupby_extension_agg(self, as_index, data_for_grouping, request):
         pa_dtype = data_for_grouping.dtype.pyarrow_dtype
@@ -1446,6 +1439,19 @@ def test_is_bool_dtype():
     tm.assert_series_equal(result, expected)
 
 
+def test_is_numeric_dtype(data):
+    # GH 50563
+    pa_type = data.dtype.pyarrow_dtype
+    if (
+        pa.types.is_floating(pa_type)
+        or pa.types.is_integer(pa_type)
+        or pa.types.is_decimal(pa_type)
+    ):
+        assert is_numeric_dtype(data)
+    else:
+        assert not is_numeric_dtype(data)
+
+
 def test_pickle_roundtrip(data):
     # GH 42600
     expected = pd.Series(data)

pandas/tests/io/json/test_json_table_schema_ext_dtype.py

@@ -48,7 +48,7 @@ def test_build_table_schema(self):
             "fields": [
                 {"name": "index", "type": "integer"},
                 {"name": "A", "type": "any", "extDtype": "DateDtype"},
-                {"name": "B", "type": "any", "extDtype": "decimal"},
+                {"name": "B", "type": "number", "extDtype": "decimal"},
                 {"name": "C", "type": "any", "extDtype": "string"},
                 {"name": "D", "type": "integer", "extDtype": "Int64"},
             ],
@@ -82,10 +82,10 @@ def test_as_json_table_type_ext_date_dtype(self):
         ],
     )
     def test_as_json_table_type_ext_decimal_array_dtype(self, decimal_data):
-        assert as_json_table_type(decimal_data.dtype) == "any"
+        assert as_json_table_type(decimal_data.dtype) == "number"
 
     def test_as_json_table_type_ext_decimal_dtype(self):
-        assert as_json_table_type(DecimalDtype()) == "any"
+        assert as_json_table_type(DecimalDtype()) == "number"
 
     @pytest.mark.parametrize(
         "string_data",
@@ -180,7 +180,7 @@ def test_build_decimal_series(self, dc):
 
         fields = [
             {"name": "id", "type": "integer"},
-            {"name": "a", "type": "any", "extDtype": "decimal"},
+            {"name": "a", "type": "number", "extDtype": "decimal"},
         ]
 
         schema = {"fields": fields, "primaryKey": ["id"]}
@@ -257,7 +257,7 @@ def test_to_json(self, df):
         fields = [
             OrderedDict({"name": "idx", "type": "integer"}),
             OrderedDict({"name": "A", "type": "any", "extDtype": "DateDtype"}),
-            OrderedDict({"name": "B", "type": "any", "extDtype": "decimal"}),
+            OrderedDict({"name": "B", "type": "number", "extDtype": "decimal"}),
             OrderedDict({"name": "C", "type": "any", "extDtype": "string"}),
             OrderedDict({"name": "D", "type": "integer", "extDtype": "Int64"}),
         ]