DEPR: BaseNoReduceTests (#54663)

* DEPR: BaseNoReduceTests

* Whatsnew

Author: jbrockmendel

doc/source/whatsnew/v2.2.0.rst

@@ -102,7 +102,7 @@ Deprecations
 - Deprecated allowing non-keyword arguments in :meth:`DataFrame.to_pickle` except ``path``. (:issue:`54229`)
 - Deprecated allowing non-keyword arguments in :meth:`DataFrame.to_string` except ``buf``. (:issue:`54229`)
 - Deprecated not passing a tuple to :class:`DataFrameGroupBy.get_group` or :class:`SeriesGroupBy.get_group` when grouping by a length-1 list-like (:issue:`25971`)
-
+- Deprecated the extension test classes ``BaseNoReduceTests``, ``BaseBooleanReduceTests``, and ``BaseNumericReduceTests``, use ``BaseReduceTests`` instead (:issue:`54663`)
 -
 
 .. ---------------------------------------------------------------------------

pandas/tests/extension/base/__init__.py

@@ -56,12 +56,7 @@ class TestMyDtype(BaseDtypeTests):
     BaseUnaryOpsTests,
 )
 from pandas.tests.extension.base.printing import BasePrintingTests
-from pandas.tests.extension.base.reduce import (  # noqa: F401
-    BaseBooleanReduceTests,
-    BaseNoReduceTests,
-    BaseNumericReduceTests,
-    BaseReduceTests,
-)
+from pandas.tests.extension.base.reduce import BaseReduceTests
 from pandas.tests.extension.base.reshaping import BaseReshapingTests
 from pandas.tests.extension.base.setitem import BaseSetitemTests
 
@@ -92,3 +87,44 @@ class ExtensionTests(
     BaseSetitemTests,
 ):
     pass
+
+
+def __getattr__(name: str):
+    import warnings
+
+    if name == "BaseNoReduceTests":
+        warnings.warn(
+            "BaseNoReduceTests is deprecated and will be removed in a "
+            "future version. Use BaseReduceTests and override "
+            "`_supports_reduction` instead.",
+            FutureWarning,
+        )
+        from pandas.tests.extension.base.reduce import BaseNoReduceTests
+
+        return BaseNoReduceTests
+
+    elif name == "BaseNumericReduceTests":
+        warnings.warn(
+            "BaseNumericReduceTests is deprecated and will be removed in a "
+            "future version. Use BaseReduceTests and override "
+            "`_supports_reduction` instead.",
+            FutureWarning,
+        )
+        from pandas.tests.extension.base.reduce import BaseNumericReduceTests
+
+        return BaseNumericReduceTests
+
+    elif name == "BaseBooleanReduceTests":
+        warnings.warn(
+            "BaseBooleanReduceTests is deprecated and will be removed in a "
+            "future version. Use BaseReduceTests and override "
+            "`_supports_reduction` instead.",
+            FutureWarning,
+        )
+        from pandas.tests.extension.base.reduce import BaseBooleanReduceTests
+
+        return BaseBooleanReduceTests
+
+    raise AttributeError(
+        f"module 'pandas.tests.extension.base' has no attribute '{name}'"
+    )

pandas/tests/extension/base/reduce.py

@@ -129,7 +129,8 @@ def test_reduce_frame(self, data, all_numeric_reductions, skipna):
         self.check_reduce_frame(ser, op_name, skipna)
 
 
-# TODO: deprecate BaseNoReduceTests, BaseNumericReduceTests, BaseBooleanReduceTests
+# TODO(3.0): remove BaseNoReduceTests, BaseNumericReduceTests,
+#  BaseBooleanReduceTests
 class BaseNoReduceTests(BaseReduceTests):
     """we don't define any reductions"""