REF: move ShallowMixin to groupby.base (#36341)

Author: jbrockmendel

pandas/core/base.py

@@ -4,7 +4,7 @@
 
 import builtins
 import textwrap
-from typing import Any, Callable, Dict, FrozenSet, List, Optional, Union
+from typing import Any, Callable, Dict, FrozenSet, Optional, Union
 
 import numpy as np
 
@@ -577,21 +577,6 @@ def _is_builtin_func(self, arg):
         return self._builtin_table.get(arg, arg)
 
 
-class ShallowMixin:
-    _attributes: List[str] = []
-
-    def _shallow_copy(self, obj, **kwargs):
-        """
-        return a new object with the replacement attributes
-        """
-        if isinstance(obj, self._constructor):
-            obj = obj.obj
-        for attr in self._attributes:
-            if attr not in kwargs:
-                kwargs[attr] = getattr(self, attr)
-        return self._constructor(obj, **kwargs)
-
-
 class IndexOpsMixin:
     """
     Common ops mixin to support a unified interface / docs for Series / Index

pandas/core/groupby/base.py

@@ -13,7 +13,22 @@
 OutputKey = collections.namedtuple("OutputKey", ["label", "position"])
 
 
-class GroupByMixin(PandasObject):
+class ShallowMixin(PandasObject):
+    _attributes: List[str] = []
+
+    def _shallow_copy(self, obj, **kwargs):
+        """
+        return a new object with the replacement attributes
+        """
+        if isinstance(obj, self._constructor):
+            obj = obj.obj
+        for attr in self._attributes:
+            if attr not in kwargs:
+                kwargs[attr] = getattr(self, attr)
+        return self._constructor(obj, **kwargs)
+
+
+class GotItemMixin(PandasObject):
     """
     Provide the groupby facilities to the mixed object.
     """

pandas/core/resample.py

@@ -22,9 +22,9 @@
 from pandas.core.dtypes.generic import ABCDataFrame, ABCSeries
 
 import pandas.core.algorithms as algos
-from pandas.core.base import DataError, ShallowMixin
+from pandas.core.base import DataError
 from pandas.core.generic import NDFrame, _shared_docs
-from pandas.core.groupby.base import GroupByMixin
+from pandas.core.groupby.base import GotItemMixin, ShallowMixin
 from pandas.core.groupby.generic import SeriesGroupBy
 from pandas.core.groupby.groupby import (
     BaseGroupBy,
@@ -954,7 +954,7 @@ def h(self, _method=method):
     setattr(Resampler, method, h)
 
 
-class _GroupByMixin(GroupByMixin):
+class _GroupByMixin(GotItemMixin):
     """
     Provide the groupby facilities.
     """

pandas/core/window/common.py

@@ -7,7 +7,7 @@
 
 from pandas.core.dtypes.generic import ABCDataFrame, ABCSeries
 
-from pandas.core.groupby.base import GroupByMixin
+from pandas.core.groupby.base import GotItemMixin
 from pandas.core.indexes.api import MultiIndex
 from pandas.core.shared_docs import _shared_docs
 
@@ -43,7 +43,7 @@ def f(x):
     return outer
 
 
-class WindowGroupByMixin(GroupByMixin):
+class WindowGroupByMixin(GotItemMixin):
     """
     Provide the groupby facilities.
     """

pandas/core/window/rolling.py

@@ -46,9 +46,10 @@
 )
 from pandas.core.dtypes.missing import notna
 
-from pandas.core.base import DataError, PandasObject, SelectionMixin, ShallowMixin
+from pandas.core.base import DataError, SelectionMixin
 import pandas.core.common as com
 from pandas.core.construction import extract_array
+from pandas.core.groupby.base import ShallowMixin
 from pandas.core.indexes.api import Index, MultiIndex
 from pandas.core.util.numba_ import NUMBA_FUNC_CACHE, maybe_use_numba
 from pandas.core.window.common import (
@@ -146,7 +147,7 @@ def func(arg, window, min_periods=None):
     return func
 
 
-class _Window(PandasObject, ShallowMixin, SelectionMixin):
+class _Window(ShallowMixin, SelectionMixin):
     _attributes: List[str] = [
         "window",
         "min_periods",