consolidate to generic.py

Author: jreback

pandas/core/groupby/__init__.py

@@ -1,5 +1,4 @@
-# flake8: noqa
-from pandas.core.groupby.groupby import GroupBy
-from pandas.core.groupby.series import SeriesGroupBy
-from pandas.core.groupby.frame import DataFrameGroupBy
-from pandas.core.groupby.ops import Grouper
+from pandas.core.groupby.groupby import GroupBy  # flake8: noqa
+from pandas.core.groupby.generic import (
+    SeriesGroupBy, DataFrameGroupBy, PanelGroupBy)  # flake8: noqa
+from pandas.core.groupby.ops import Grouper  # flake8: noqa

pandas/core/groupby/base.py

@@ -3,8 +3,8 @@
 """
 
 import types
-from pandas.core.dtypes.common import is_scalar, is_list_like
 from pandas.util._decorators import make_signature
+from pandas.core.dtypes.common import is_scalar, is_list_like
 
 
 class GroupByMixin(object):