style fixes

pandas/core/dtypes/concat.py

@@ -103,14 +103,23 @@ def _get_frame_result_type(result, objs):
 
 def _get_sliced_frame_result_type(data, obj):
     """
-    return appropriate class of Series depending on whether
-    the data is sparse or not.
+    return appropriate class of Series. When data is sparse
+    it will return a SparseSeries, otherwise it will return
+    the Series.
+
+    Parameters
+    ----------
+    data : ndarray
+    obj : DataFrame
+
+    Returns
+    -------
+    Series or SparseSeries
     """
     if is_sparse(data):
         from pandas.core.sparse.api import SparseSeries
         return SparseSeries
-    else:
-        return obj._constructor_sliced
+    return obj._constructor_sliced
 
 
 def _concat_compat(to_concat, axis=0):

pandas/core/frame.py

@@ -60,6 +60,7 @@
     is_iterator,
     is_sequence,
     is_named_tuple)
+from pandas.core.dtypes.concat import _get_sliced_frame_result_type
 from pandas.core.dtypes.missing import isna, notna
 
 
@@ -2562,10 +2563,8 @@ def _box_item_values(self, key, values):
 
     def _box_col_values(self, values, items):
         """ provide boxed values for a column """
-        from pandas.core.dtypes.concat import _get_sliced_frame_result_type
-        this_constructor_sliced = _get_sliced_frame_result_type(values, self)
-        return this_constructor_sliced(values, index=self.index,
-                                       name=items, fastpath=True)
+        klass = _get_sliced_frame_result_type(values, self)
+        return klass(values, index=self.index, name=items, fastpath=True)
 
     def __setitem__(self, key, value):
         key = com._apply_if_callable(key, self)