From 3a95a191fea55cd3985f312f3154452be3e3d2b6 Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Wed, 28 Apr 2021 14:09:05 -0700
Subject: [PATCH 01/20] Create a new 1d frame class and implement a name for
 them.

---
 python/cudf/cudf/core/frame.py  | 17 +++++++++++++++++
 python/cudf/cudf/core/index.py  | 34 +++++++++++----------------------
 python/cudf/cudf/core/series.py | 15 ++-------------
 3 files changed, 30 insertions(+), 36 deletions(-)

diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index 5c4186c4ac7..4fc2e3990fb 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -3295,6 +3295,23 @@ def _reindex(
         return self._mimic_inplace(result, inplace=inplace)
 
 
+class FrameOneD(Frame):
+    """A one-dimensional frame.
+
+    Frames with only a single dimension share certain logic that is encoded in
+    this class.
+    """
+
+    @property
+    def name(self):
+        """The name of this object."""
+        return next(iter(self._data.names))
+
+    @name.setter
+    def name(self, value):
+        self._data[value] = self._data.pop(self.name)
+
+
 def _get_replacement_values_for_columns(
     to_replace: Any, value: Any, columns_dtype_map: Dict[Any, Any]
 ) -> Tuple[Dict[Any, bool], Dict[Any, Any], Dict[Any, Any]]:
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index 0ffe0c11fef..786bf44bb74 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -29,7 +29,7 @@
 )
 from cudf.core.column.string import StringMethods as StringMethods
 from cudf.core.dtypes import IntervalDtype
-from cudf.core.frame import Frame
+from cudf.core.frame import FrameOneD
 from cudf.utils import ioutils
 from cudf.utils.docutils import copy_docstring
 from cudf.utils.dtypes import (
@@ -73,7 +73,7 @@ def _to_frame(this_index, index=True, name=None):
     )
 
 
-class Index(Frame, Serializable):
+class Index(FrameOneD, Serializable):
 
     dtype: DtypeObj
 
@@ -388,18 +388,6 @@ def names(self, values):
 
         self.name = values[0]
 
-    @property
-    def name(self):
-        """
-        Returns the name of the Index.
-        """
-        return next(iter(self._data.names))
-
-    @name.setter
-    def name(self, value):
-        col = self._data.pop(self.name)
-        self._data[value] = col
-
     def dropna(self, how="any"):
         """
         Return an Index with null values removed.
@@ -1557,7 +1545,7 @@ def _from_table(cls, table):
 
     @classmethod
     def _from_data(cls, data, index=None):
-        return cls._from_table(Frame(data=data))
+        return cls._from_table(FrameOneD(data=data))
 
     _accessors = set()  # type: Set[Any]
 
@@ -1606,7 +1594,7 @@ def __new__(
         if step == 0:
             raise ValueError("Step must not be zero.")
 
-        out = Frame.__new__(cls)
+        out = FrameOneD.__new__(cls)
         if isinstance(start, range):
             therange = start
             start = therange.start
@@ -1978,7 +1966,7 @@ def __new__(cls, values, **kwargs):
             Column's name. Otherwise if this name is different from the value
             Column's, the values Column will be cloned to adopt this name.
         """
-        out = Frame.__new__(cls)
+        out = FrameOneD.__new__(cls)
         out._initialize(values, **kwargs)
 
         return out
@@ -2201,7 +2189,7 @@ class NumericIndex(GenericIndex):
 
     def __new__(cls, data=None, dtype=None, copy=False, name=None):
 
-        out = Frame.__new__(cls)
+        out = FrameOneD.__new__(cls)
         dtype = _index_to_dtype[cls]
         if copy:
             data = column.as_column(data, dtype=dtype).copy()
@@ -2323,7 +2311,7 @@ def __new__(
         # pandas dtindex creation first which.  For now
         # just make sure we handle np.datetime64 arrays
         # and then just dispatch upstream
-        out = Frame.__new__(cls)
+        out = FrameOneD.__new__(cls)
 
         if freq is not None:
             raise NotImplementedError("Freq is not yet supported")
@@ -2578,7 +2566,7 @@ def __new__(
         name=None,
     ) -> "TimedeltaIndex":
 
-        out = Frame.__new__(cls)
+        out = FrameOneD.__new__(cls)
 
         if freq is not None:
             raise NotImplementedError("freq is not yet supported")
@@ -2710,7 +2698,7 @@ def __new__(
                 )
         if copy:
             data = column.as_column(data, dtype=dtype).copy(deep=True)
-        out = Frame.__new__(cls)
+        out = FrameOneD.__new__(cls)
         kwargs = _setdefault_name(data, name=name)
         if isinstance(data, CategoricalColumn):
             data = data
@@ -2936,7 +2924,7 @@ def __new__(
     ) -> "IntervalIndex":
         if copy:
             data = column.as_column(data, dtype=dtype).copy()
-        out = Frame.__new__(cls)
+        out = FrameOneD.__new__(cls)
         kwargs = _setdefault_name(data, name=name)
         if isinstance(data, IntervalColumn):
             data = data
@@ -3009,7 +2997,7 @@ class StringIndex(GenericIndex):
     """
 
     def __new__(cls, values, copy=False, **kwargs):
-        out = Frame.__new__(cls)
+        out = FrameOneD.__new__(cls)
         kwargs = _setdefault_name(values, **kwargs)
         if isinstance(values, StringColumn):
             values = values.copy(deep=copy)
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index 4cc5fb56a4c..afe4f8e25ed 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -38,7 +38,7 @@
 from cudf.core.column.string import StringMethods
 from cudf.core.column.struct import StructMethods
 from cudf.core.column_accessor import ColumnAccessor
-from cudf.core.frame import Frame, _drop_rows_by_labels
+from cudf.core.frame import FrameOneD, _drop_rows_by_labels
 from cudf.core.groupby.groupby import SeriesGroupBy
 from cudf.core.index import Index, RangeIndex, as_index
 from cudf.core.indexing import _SeriesIlocIndexer, _SeriesLocIndexer
@@ -61,7 +61,7 @@
 )
 
 
-class Series(Frame, Serializable):
+class Series(FrameOneD, Serializable):
     @property
     def _constructor(self):
         return Series
@@ -441,17 +441,6 @@ def ndim(self):
         """
         return 1
 
-    @property
-    def name(self):
-        """Returns name of the Series.
-        """
-        return self._data.names[0]
-
-    @name.setter
-    def name(self, value):
-        col = self._data.pop(self.name)
-        self._data[value] = col
-
     @classmethod
     def deserialize(cls, header, frames):
         index_nframes = header["index_frame_count"]

From a2718d179717dcdbd39943e8a50654fcf208fd4a Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Wed, 28 Apr 2021 14:11:25 -0700
Subject: [PATCH 02/20] Move ndim.

---
 python/cudf/cudf/core/frame.py  | 5 +++++
 python/cudf/cudf/core/index.py  | 6 ------
 python/cudf/cudf/core/series.py | 6 ------
 3 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index 4fc2e3990fb..807663559ca 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -3311,6 +3311,11 @@ def name(self):
     def name(self, value):
         self._data[value] = self._data.pop(self.name)
 
+    @property
+    def ndim(self):
+        """Dimension of the data (always 1)."""
+        return 1
+
 
 def _get_replacement_values_for_columns(
     to_replace: Any, value: Any, columns_dtype_map: Dict[Any, Any]
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index 786bf44bb74..af649a883b8 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -362,12 +362,6 @@ def deserialize(cls, header, frames):
         index = col_typ.deserialize(h, frames[: header["frame_count"]])
         return idx_typ(index, name=name)
 
-    @property
-    def ndim(self):
-        """Dimension of the data. Apart from MultiIndex ndim is always 1.
-        """
-        return 1
-
     @property
     def names(self):
         """
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index afe4f8e25ed..c63baf1be6f 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -435,12 +435,6 @@ def dt(self):
                 "Can only use .dt accessor with datetimelike values"
             )
 
-    @property
-    def ndim(self):
-        """Dimension of the data. Series ndim is always 1.
-        """
-        return 1
-
     @classmethod
     def deserialize(cls, header, frames):
         index_nframes = header["index_frame_count"]

From b176e5480938d5e6dde06dfc97a875448f74851b Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Wed, 28 Apr 2021 14:17:38 -0700
Subject: [PATCH 03/20] Remove unnecessary constructor property.

---
 python/cudf/cudf/core/dataframe.py       | 6 +-----
 python/cudf/cudf/core/frame.py           | 2 +-
 python/cudf/cudf/core/series.py          | 8 ++------
 python/cudf/cudf/tests/test_dataframe.py | 6 ------
 4 files changed, 4 insertions(+), 18 deletions(-)

diff --git a/python/cudf/cudf/core/dataframe.py b/python/cudf/cudf/core/dataframe.py
index 131463e8871..179dc14ccb3 100644
--- a/python/cudf/cudf/core/dataframe.py
+++ b/python/cudf/cudf/core/dataframe.py
@@ -554,10 +554,6 @@ def _align_input_series_indices(data, index):
 
         return data, index
 
-    @property
-    def _constructor(self):
-        return DataFrame
-
     @property
     def _constructor_sliced(self):
         return Series
@@ -1456,7 +1452,7 @@ def _get_columns_by_label(self, labels, downcast=False):
                     new_data, index=self.index, name=labels
                 )
                 return out
-        out = self._constructor()._from_data(
+        out = self.__class__()._from_data(
             new_data, index=self.index, columns=new_data.to_pandas_index()
         )
         return out
diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index 807663559ca..0147d452811 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -608,7 +608,7 @@ def _get_columns_by_index(self, indices):
 
         """
         data = self._data.select_by_index(indices)
-        return self._constructor(
+        return self.__class__(
             data, columns=data.to_pandas_index(), index=self.index
         )
 
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index c63baf1be6f..124a0f5f7ac 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -62,10 +62,6 @@
 
 
 class Series(FrameOneD, Serializable):
-    @property
-    def _constructor(self):
-        return Series
-
     @property
     def _constructor_sliced(self):
         raise NotImplementedError(
@@ -470,9 +466,9 @@ def _get_columns_by_label(self, labels, downcast=False):
         new_data = super()._get_columns_by_label(labels, downcast)
 
         return (
-            self._constructor(data=new_data, index=self.index)
+            self.__class__(data=new_data, index=self.index)
             if len(new_data) > 0
-            else self._constructor(dtype=self.dtype, name=self.name)
+            else self.__class__(dtype=self.dtype, name=self.name)
         )
 
     @classmethod
diff --git a/python/cudf/cudf/tests/test_dataframe.py b/python/cudf/cudf/tests/test_dataframe.py
index 06b08d79093..5ae678d6839 100644
--- a/python/cudf/cudf/tests/test_dataframe.py
+++ b/python/cudf/cudf/tests/test_dataframe.py
@@ -4377,12 +4377,6 @@ def test_constructor_properties():
     df[key1] = val1
     df[key2] = val2
 
-    # Correct use of _constructor (for DataFrame)
-    assert_eq(df, df._constructor({key1: val1, key2: val2}))
-
-    # Correct use of _constructor (for cudf.Series)
-    assert_eq(df[key1], df[key2]._constructor(val1, name=key1))
-
     # Correct use of _constructor_sliced (for DataFrame)
     assert_eq(df[key1], df._constructor_sliced(val1, name=key1))
 

From 90e112c5338c7f0cef69808fc85154cfb6fd1999 Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Wed, 28 Apr 2021 14:20:44 -0700
Subject: [PATCH 04/20] Move shape.

---
 python/cudf/cudf/core/frame.py  | 6 ++++++
 python/cudf/cudf/core/index.py  | 6 ------
 python/cudf/cudf/core/series.py | 6 ------
 3 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index 0147d452811..0957c1466c5 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -3316,6 +3316,12 @@ def ndim(self):
         """Dimension of the data (always 1)."""
         return 1
 
+    @property
+    def shape(self):
+        """Returns a tuple representing the dimensionality of the Index.
+        """
+        return (len(self),)
+
 
 def _get_replacement_values_for_columns(
     to_replace: Any, value: Any, columns_dtype_map: Dict[Any, Any]
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index af649a883b8..57cf977a2c9 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -180,12 +180,6 @@ def drop_duplicates(self, keep="first"):
         """  # noqa: E501
         return super().drop_duplicates(keep=keep)
 
-    @property
-    def shape(self):
-        """Returns a tuple representing the dimensionality of the Index.
-        """
-        return (len(self),)
-
     def serialize(self):
         header = {}
         header["index_column"] = {}
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index 124a0f5f7ac..f020be286ae 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -397,12 +397,6 @@ def serialize(self):
 
         return header, frames
 
-    @property
-    def shape(self):
-        """Returns a tuple representing the dimensionality of the Series.
-        """
-        return (len(self),)
-
     @property
     def dt(self):
         """

From b99444fc3656eb3a3d48e45e10f8aa1db0a70e2e Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Wed, 28 Apr 2021 15:11:01 -0700
Subject: [PATCH 05/20] Move __iter__.

---
 python/cudf/cudf/core/frame.py  | 3 +++
 python/cudf/cudf/core/index.py  | 3 ---
 python/cudf/cudf/core/series.py | 7 ++-----
 3 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index 0957c1466c5..db782ad7371 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -3322,6 +3322,9 @@ def shape(self):
         """
         return (len(self),)
 
+    def __iter__(self):
+        cudf.utils.utils.raise_iteration_error(obj=self)
+
 
 def _get_replacement_values_for_columns(
     to_replace: Any, value: Any, columns_dtype_map: Dict[Any, Any]
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index 57cf977a2c9..d583d22cb60 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -271,9 +271,6 @@ def get_level_values(self, level):
         else:
             raise KeyError(f"Requested level with name {level} " "not found")
 
-    def __iter__(self):
-        cudf.utils.utils.raise_iteration_error(obj=self)
-
     @classmethod
     def from_arrow(cls, array):
         """Convert PyArrow Array/ChunkedArray to Index
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index f020be286ae..3e9a7d98963 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -1159,12 +1159,9 @@ def __getitem__(self, arg):
         else:
             return self.loc[arg]
 
-    def __iter__(self):
-        cudf.utils.utils.raise_iteration_error(obj=self)
+    iteritems = FrameOneD.__iter__
 
-    iteritems = __iter__
-
-    items = __iter__
+    items = FrameOneD.__iter__
 
     def to_dict(self, into=dict):
         raise TypeError(

From 58f0a236d42ed3d10a7dccf79011dcaf2a741a55 Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Wed, 28 Apr 2021 15:46:22 -0700
Subject: [PATCH 06/20] Rename index._values to index._column.

---
 python/cudf/cudf/core/column/categorical.py |  12 +-
 python/cudf/cudf/core/column/column.py      |   2 +-
 python/cudf/cudf/core/dataframe.py          |   2 +-
 python/cudf/cudf/core/frame.py              |   4 +-
 python/cudf/cudf/core/index.py              | 126 ++++++++++----------
 python/cudf/cudf/core/indexing.py           |   6 +-
 python/cudf/cudf/core/series.py             |   4 +-
 python/cudf/cudf/tests/test_dataframe.py    |  10 +-
 python/cudf/cudf/tests/test_index.py        |  30 ++---
 9 files changed, 96 insertions(+), 100 deletions(-)

diff --git a/python/cudf/cudf/core/column/categorical.py b/python/cudf/cudf/core/column/categorical.py
index 3cd1a599ddc..1e11138fcf0 100644
--- a/python/cudf/cudf/core/column/categorical.py
+++ b/python/cudf/cudf/core/column/categorical.py
@@ -918,7 +918,7 @@ def as_numerical(self) -> NumericalColumn:
 
     @property
     def categories(self) -> ColumnBase:
-        return self.dtype.categories._values
+        return self.dtype.categories._column
 
     @categories.setter
     def categories(self, value):
@@ -1044,7 +1044,7 @@ def normalize_binop_value(self, other: ScalarLike) -> CategoricalColumn:
             self._encode(other), size=len(self), dtype=self.codes.dtype
         )
         col = column.build_categorical_column(
-            categories=self.dtype.categories._values,
+            categories=self.dtype.categories._column,
             codes=column.as_column(ary),
             mask=self.base_mask,
             ordered=self.dtype.ordered,
@@ -1056,7 +1056,7 @@ def sort_by_values(
     ) -> Tuple[CategoricalColumn, NumericalColumn]:
         codes, inds = self.as_numerical.sort_by_values(ascending, na_position)
         col = column.build_categorical_column(
-            categories=self.dtype.categories._values,
+            categories=self.dtype.categories._column,
             codes=column.as_column(codes.base_data, dtype=codes.dtype),
             mask=codes.base_mask,
             size=codes.size,
@@ -1317,7 +1317,7 @@ def fillna(
         result = super().fillna(value=fill_value, method=method)
 
         result = column.build_categorical_column(
-            categories=self.dtype.categories._values,
+            categories=self.dtype.categories._column,
             codes=column.as_column(result.base_data, dtype=result.dtype),
             offset=result.offset,
             size=result.size,
@@ -1381,7 +1381,7 @@ def as_categorical_column(
         if not isinstance(dtype, CategoricalDtype):
             raise ValueError("dtype must be CategoricalDtype")
 
-        if not isinstance(self.categories, type(dtype.categories._values)):
+        if not isinstance(self.categories, type(dtype.categories._column)):
             # If both categories are of different Column types,
             # return a column full of Nulls.
             return _create_empty_categorical_column(self, dtype)
@@ -1434,7 +1434,7 @@ def copy(self, deep: bool = True) -> CategoricalColumn:
             )
         else:
             return column.build_categorical_column(
-                categories=self.dtype.categories._values,
+                categories=self.dtype.categories._column,
                 codes=column.as_column(
                     self.codes.base_data, dtype=self.codes.dtype
                 ),
diff --git a/python/cudf/cudf/core/column/column.py b/python/cudf/cudf/core/column/column.py
index 0f039b137bc..509925d7a97 100644
--- a/python/cudf/cudf/core/column/column.py
+++ b/python/cudf/cudf/core/column/column.py
@@ -1802,7 +1802,7 @@ def as_column(
         if dtype is not None:
             data = data.astype(dtype)
     elif isinstance(arbitrary, cudf.Index):
-        data = arbitrary._values
+        data = arbitrary._column
         if dtype is not None:
             data = data.astype(dtype)
 
diff --git a/python/cudf/cudf/core/dataframe.py b/python/cudf/cudf/core/dataframe.py
index 179dc14ccb3..fc087d56b4d 100644
--- a/python/cudf/cudf/core/dataframe.py
+++ b/python/cudf/cudf/core/dataframe.py
@@ -8001,7 +8001,7 @@ def _get_union_of_indices(indexes):
     else:
         merged_index = cudf.core.Index._concat(indexes)
         merged_index = merged_index.drop_duplicates()
-        _, inds = merged_index._values.sort_by_values()
+        _, inds = merged_index._column.sort_by_values()
         return merged_index.take(inds)
 
 
diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index db782ad7371..3dc381ac4ca 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -475,9 +475,9 @@ def _concat(
             )
             if not isinstance(
                 out._index, cudf.MultiIndex
-            ) and is_categorical_dtype(out._index._values.dtype):
+            ) and is_categorical_dtype(out._index._column.dtype):
                 out = out.set_index(
-                    cudf.core.index.as_index(out.index._values)
+                    cudf.core.index.as_index(out.index._column)
                 )
 
         # Reassign index and column names
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index d583d22cb60..e91cb630da0 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -69,7 +69,7 @@ def _to_frame(this_index, index=True, name=None):
         col_name = this_index.name
 
     return cudf.DataFrame(
-        {col_name: this_index._values}, index=this_index if index else None
+        {col_name: this_index._column}, index=this_index if index else None
     )
 
 
@@ -145,9 +145,9 @@ def __init__(
         """
         pass
 
-    @cached_property
-    def _values(self) -> ColumnBase:
-        raise NotImplementedError
+    @property
+    def _column(self):
+        return self._data[self.name]
 
     def __getitem__(self, key):
         raise NotImplementedError()
@@ -185,7 +185,7 @@ def serialize(self):
         header["index_column"] = {}
         # store metadata values of index separately
         # Indexes: Numerical/DateTime/String are often GPU backed
-        header["index_column"], frames = self._values.serialize()
+        header["index_column"], frames = self._column.serialize()
 
         header["name"] = pickle.dumps(self.name)
         header["dtype"] = pickle.dumps(self.dtype)
@@ -194,7 +194,7 @@ def serialize(self):
         return header, frames
 
     def __contains__(self, item):
-        return item in self._values
+        return item in self._column
 
     @annotate("INDEX_EQUALS", color="green", domain="cudf_python")
     def equals(self, other, **kwargs):
@@ -341,7 +341,7 @@ def values_host(self):
         >>> type(index.values_host)
         <class 'numpy.ndarray'>
         """
-        return self._values.values_host
+        return self._column.values_host
 
     @classmethod
     def deserialize(cls, header, frames):
@@ -428,9 +428,9 @@ def _clean_nulls_from_index(self):
         methods using this method to replace or handle representation
         of the actual types correctly.
         """
-        if self._values.has_nulls:
+        if self._column.has_nulls:
             return cudf.Index(
-                self._values.astype("str").fillna(cudf._NA_REP), name=self.name
+                self._column.astype("str").fillna(cudf._NA_REP), name=self.name
             )
         else:
             return self
@@ -611,7 +611,7 @@ def argsort(self, ascending=True, **kwargs):
         >>> index.argsort(ascending=False)
         array([3, 2, 1, 0, 4], dtype=int32)
         """
-        indices = self._values.argsort(ascending=ascending, **kwargs)
+        indices = self._column.argsort(ascending=ascending, **kwargs)
         return cupy.asarray(indices)
 
     @property
@@ -632,13 +632,13 @@ def values(self):
         >>> type(index.values)
         <class 'cupy.core.core.ndarray'>
         """
-        return self._values.values
+        return self._column.values
 
     def any(self):
         """
         Return whether any elements is True in Index.
         """
-        return self._values.any()
+        return self._column.any()
 
     def to_pandas(self):
         """
@@ -657,7 +657,7 @@ def to_pandas(self):
         >>> type(idx)
         <class 'cudf.core.index.GenericIndex'>
         """
-        return pd.Index(self._values.to_pandas(), name=self.name)
+        return pd.Index(self._column.to_pandas(), name=self.name)
 
     def tolist(self):
 
@@ -680,7 +680,7 @@ def gpu_values(self):
         """
         View the data as a numba device array object
         """
-        return self._values.data_array_view
+        return self._column.data_array_view
 
     def min(self):
         """
@@ -705,7 +705,7 @@ def min(self):
         >>> idx.min()
         1
         """
-        return self._values.min()
+        return self._column.min()
 
     def max(self):
         """
@@ -730,7 +730,7 @@ def max(self):
         >>> idx.max()
         3
         """
-        return self._values.max()
+        return self._column.max()
 
     def sum(self):
         """
@@ -748,11 +748,11 @@ def sum(self):
         >>> idx.sum()
         6
         """
-        return self._values.sum()
+        return self._column.sum()
 
     @classmethod
     def _concat(cls, objs):
-        data = ColumnBase._concat([o._values for o in objs])
+        data = ColumnBase._concat([o._column for o in objs])
         names = {obj.name for obj in objs}
         if len(names) == 1:
             [name] = names
@@ -820,7 +820,7 @@ def append(self, other):
                         f"either one of them to same dtypes."
                     )
 
-                if isinstance(self._values, cudf.core.column.NumericalColumn):
+                if isinstance(self._column, cudf.core.column.NumericalColumn):
                     if self.dtype != other.dtype:
                         this, other = numeric_normalize_types(self, other)
                 to_concat = [this, other]
@@ -974,7 +974,7 @@ def sort_values(self, return_indexer=False, ascending=True, key=None):
         if key is not None:
             raise NotImplementedError("key parameter is not yet implemented.")
 
-        indices = self._values.argsort(ascending=ascending)
+        indices = self._column.argsort(ascending=ascending)
         index_sorted = as_index(self.take(indices), name=self.name)
 
         if return_indexer:
@@ -990,7 +990,7 @@ def unique(self):
         -------
         Index without duplicates
         """
-        return as_index(self._values.unique(), name=self.name)
+        return as_index(self._column.unique(), name=self.name)
 
     def __add__(self, other):
         return self._apply_op("__add__", other)
@@ -1219,7 +1219,7 @@ def astype(self, dtype, copy=False):
             return self.copy(deep=copy)
 
         return as_index(
-            self.copy(deep=copy)._values.astype(dtype), name=self.name
+            self.copy(deep=copy)._column.astype(dtype), name=self.name
         )
 
     def to_array(self, fillna=None):
@@ -1238,7 +1238,7 @@ def to_array(self, fillna=None):
         if ``fillna`` is ``None``, null values are skipped.  Therefore, the
         output size could be smaller.
         """
-        return self._values.to_array(fillna=fillna)
+        return self._column.to_array(fillna=fillna)
 
     def to_series(self, index=None, name=None):
         """
@@ -1260,7 +1260,7 @@ def to_series(self, index=None, name=None):
         """
 
         return cudf.Series(
-            self._values,
+            self._column,
             index=self.copy(deep=False) if index is None else index,
             name=self.name if name is None else name,
         )
@@ -1285,7 +1285,7 @@ def is_monotonic_increasing(self):
         Return if the index is monotonic increasing
         (only equal or increasing) values.
         """
-        return self._values.is_monotonic_increasing
+        return self._column.is_monotonic_increasing
 
     @property
     def is_monotonic_decreasing(self):
@@ -1293,7 +1293,7 @@ def is_monotonic_decreasing(self):
         Return if the index is monotonic decreasing
         (only equal or decreasing) values.
         """
-        return self._values.is_monotonic_decreasing
+        return self._column.is_monotonic_decreasing
 
     @property
     def empty(self):
@@ -1452,7 +1452,7 @@ def memory_usage(self, deep=False):
         -------
             bytes used
         """
-        return self._values._memory_usage(deep=deep)
+        return self._column._memory_usage(deep=deep)
 
     @classmethod
     def from_pandas(cls, index, nan_as_null=None):
@@ -1636,7 +1636,7 @@ def _num_rows(self):
         return len(self)
 
     @cached_property
-    def _values(self):
+    def _column(self):
         if len(self) > 0:
             return column.arange(
                 self._start, self._stop, self._step, dtype=self.dtype
@@ -1647,7 +1647,7 @@ def _values(self):
     @property
     def _data(self):
         return cudf.core.column_accessor.ColumnAccessor(
-            {self.name: self._values}
+            {self.name: self._column}
         )
 
     def __contains__(self, item):
@@ -1729,7 +1729,7 @@ def __getitem__(self, index):
                 index = np.min_scalar_type(index).type(index)
             index = column.as_column(index)
 
-        return as_index(self._values[index], name=self.name)
+        return as_index(self._column[index], name=self.name)
 
     def __eq__(self, other):
         return super(type(self), self).__eq__(other)
@@ -1846,7 +1846,7 @@ def to_gpu_array(self, fillna=None):
         if ``fillna`` is ``None``, null values are skipped.  Therefore, the
         output size could be smaller.
         """
-        return self._values.to_gpu_array(fillna=fillna)
+        return self._column.to_gpu_array(fillna=fillna)
 
     def to_pandas(self):
         return pd.RangeIndex(
@@ -1916,7 +1916,7 @@ def get_slice_bound(self, label, side, kind=None):
 
     @property
     def __cuda_array_interface__(self):
-        return self._values.__cuda_array_interface__
+        return self._column.__cuda_array_interface__
 
     def memory_usage(self, **kwargs):
         return 0
@@ -1936,7 +1936,7 @@ class GenericIndex(Index):
 
     Attributes
     ----------
-    _values: A Column object
+    _column: A Column object
     name: A string
     """
 
@@ -1977,10 +1977,6 @@ def _initialize(self, values, **kwargs):
         name = kwargs.get("name")
         super(Index, self).__init__({name: values})
 
-    @property
-    def _values(self):
-        return next(iter(self._data.columns))
-
     def copy(self, name=None, deep=False, dtype=None, names=None):
         """
         Make a copy of this object.
@@ -2006,18 +2002,18 @@ def copy(self, name=None, deep=False, dtype=None, names=None):
         name = self.name if name is None else name
 
         if isinstance(self, (StringIndex, CategoricalIndex)):
-            result = as_index(self._values.astype(dtype), name=name, copy=deep)
+            result = as_index(self._column.astype(dtype), name=name, copy=deep)
         else:
             result = as_index(
-                self._values.copy(deep=deep).astype(dtype), name=name
+                self._column.copy(deep=deep).astype(dtype), name=name
             )
         return result
 
     def __sizeof__(self):
-        return self._values.__sizeof__()
+        return self._column.__sizeof__()
 
     def __len__(self):
-        return len(self._values)
+        return len(self._column)
 
     def __repr__(self):
         max_seq_items = get_option("max_seq_items") or len(self)
@@ -2059,7 +2055,7 @@ def __repr__(self):
                 output = preprocess.to_pandas().__repr__()
 
             output = output.replace("nan", cudf._NA_REP)
-        elif preprocess._values.nullable:
+        elif preprocess._column.nullable:
             output = self._clean_nulls_from_index().to_pandas().__repr__()
 
             if not isinstance(self, StringIndex):
@@ -2100,7 +2096,7 @@ def __getitem__(self, index):
             raise NotImplementedError(
                 "Getting a scalar from an IntervalIndex is not yet supported"
             )
-        res = self._values[index]
+        res = self._column[index]
         if not isinstance(index, int):
             res = as_index(res)
             res.name = self.name
@@ -2117,7 +2113,7 @@ def dtype(self):
         """
         `dtype` of the underlying values in GenericIndex.
         """
-        return self._values.dtype
+        return self._column.dtype
 
     def find_label_range(self, first, last):
         """Find range that starts with *first* and ends with *last*,
@@ -2129,7 +2125,7 @@ def find_label_range(self, first, last):
             The starting index and the ending index.
             The *last* value occurs at ``end - 1`` position.
         """
-        col = self._values
+        col = self._column
         begin, end = None, None
         if first is not None:
             begin = col.find_first_value(first, closest=True)
@@ -2143,14 +2139,14 @@ def is_unique(self):
         """
         Return if the index has unique values.
         """
-        return self._values.is_unique
+        return self._column.is_unique
 
     def get_slice_bound(self, label, side, kind):
-        return self._values.get_slice_bound(label, side, kind)
+        return self._column.get_slice_bound(label, side, kind)
 
     @property
     def __cuda_array_interface__(self):
-        return self._values.__cuda_array_interface__
+        return self._column.__cuda_array_interface__
 
 
 class NumericIndex(GenericIndex):
@@ -2482,11 +2478,11 @@ def dayofweek(self):
         return self._get_dt_field("weekday")
 
     def to_pandas(self):
-        nanos = self._values.astype("datetime64[ns]")
+        nanos = self._column.astype("datetime64[ns]")
         return pd.DatetimeIndex(nanos.to_pandas(), name=self.name)
 
     def _get_dt_field(self, field):
-        out_column = self._values.get_dt_field(field)
+        out_column = self._column.get_dt_field(field)
         # column.column_empty_like always returns a Column object
         # but we need a NumericalColumn for GenericIndex..
         # how should this be handled?
@@ -2576,9 +2572,9 @@ def __new__(
 
     def to_pandas(self):
         return pd.TimedeltaIndex(
-            self._values.to_pandas(),
+            self._column.to_pandas(),
             name=self.name,
-            unit=self._values.time_unit,
+            unit=self._column.time_unit,
         )
 
     @property
@@ -2586,21 +2582,21 @@ def days(self):
         """
         Number of days for each element.
         """
-        return as_index(arbitrary=self._values.days, name=self.name)
+        return as_index(arbitrary=self._column.days, name=self.name)
 
     @property
     def seconds(self):
         """
         Number of seconds (>= 0 and less than 1 day) for each element.
         """
-        return as_index(arbitrary=self._values.seconds, name=self.name)
+        return as_index(arbitrary=self._column.seconds, name=self.name)
 
     @property
     def microseconds(self):
         """
         Number of microseconds (>= 0 and less than 1 second) for each element.
         """
-        return as_index(arbitrary=self._values.microseconds, name=self.name)
+        return as_index(arbitrary=self._column.microseconds, name=self.name)
 
     @property
     def nanoseconds(self):
@@ -2608,7 +2604,7 @@ def nanoseconds(self):
         Number of nanoseconds (>= 0 and less than 1 microsecond) for each
         element.
         """
-        return as_index(arbitrary=self._values.nanoseconds, name=self.name)
+        return as_index(arbitrary=self._column.nanoseconds, name=self.name)
 
     @property
     def components(self):
@@ -2616,7 +2612,7 @@ def components(self):
         Return a dataframe of the components (days, hours, minutes,
         seconds, milliseconds, microseconds, nanoseconds) of the Timedeltas.
         """
-        return self._values.components()
+        return self._column.components()
 
     @property
     def inferred_freq(self):
@@ -2732,14 +2728,14 @@ def codes(self):
         """
         The category codes of this categorical.
         """
-        return self._values.cat().codes
+        return self._column.cat().codes
 
     @property
     def categories(self):
         """
         The categories of this categorical.
         """
-        return self._values.cat().categories
+        return self._column.cat().categories
 
 
 def interval_range(
@@ -2977,7 +2973,7 @@ class StringIndex(GenericIndex):
 
     Attributes
     ----------
-    _values: A StringColumn object or NDArray of strings
+    _column: A StringColumn object or NDArray of strings
     name: A string
     """
 
@@ -2987,7 +2983,7 @@ def __new__(cls, values, copy=False, **kwargs):
         if isinstance(values, StringColumn):
             values = values.copy(deep=copy)
         elif isinstance(values, StringIndex):
-            values = values._values.copy(deep=copy)
+            values = values._column.copy(deep=copy)
         else:
             values = column.as_column(values, dtype="str")
             if not pd.api.types.is_string_dtype(values.dtype):
@@ -3002,11 +2998,11 @@ def to_pandas(self):
         return pd.Index(self.to_array(), name=self.name, dtype="object")
 
     def take(self, indices):
-        return self._values[indices]
+        return self._column[indices]
 
     def __repr__(self):
         return (
-            f"{self.__class__.__name__}({self._values.to_array()},"
+            f"{self.__class__.__name__}({self._column.to_array()},"
             f" dtype='object'"
             + (
                 f", name={pd.io.formats.printing.default_pprint(self.name)}"
@@ -3019,14 +3015,14 @@ def __repr__(self):
     @copy_docstring(StringMethods.__init__)  # type: ignore
     @property
     def str(self):
-        return StringMethods(column=self._values, parent=self)
+        return StringMethods(column=self._column, parent=self)
 
     def _clean_nulls_from_index(self):
         """
         Convert all na values(if any) in Index object
         to `<NA>` as a preprocessing step to `__repr__` methods.
         """
-        if self._values.has_nulls:
+        if self._column.has_nulls:
             return self.fillna(cudf._NA_REP)
         else:
             return self
diff --git a/python/cudf/cudf/core/indexing.py b/python/cudf/cudf/core/indexing.py
index 7970b9fa3dc..42d309d7054 100755
--- a/python/cudf/cudf/core/indexing.py
+++ b/python/cudf/cudf/core/indexing.py
@@ -30,7 +30,7 @@ def indices_from_labels(obj, labels):
 
         if is_categorical_dtype(obj.index):
             labels = labels.astype("category")
-            codes = labels.codes.astype(obj.index._values.codes.dtype)
+            codes = labels.codes.astype(obj.index._column.codes.dtype)
             labels = column.build_categorical_column(
                 categories=labels.dtype.categories,
                 codes=codes,
@@ -154,7 +154,7 @@ def __setitem__(self, key, value):
                 and not isinstance(self._sr.index, cudf.MultiIndex)
                 and is_scalar(value)
             ):
-                _append_new_row_inplace(self._sr.index._values, key)
+                _append_new_row_inplace(self._sr.index._column, key)
                 _append_new_row_inplace(self._sr._column, value)
                 return
             else:
@@ -177,7 +177,7 @@ def _loc_to_iloc(self, arg):
                     found_index = arg
                     return found_index
             try:
-                found_index = self._sr.index._values.find_first_value(
+                found_index = self._sr.index._column.find_first_value(
                     arg, closest=False
                 )
                 return found_index
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index 3e9a7d98963..bb04353832a 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -217,7 +217,7 @@ def __init__(
             data = data.values
         elif isinstance(data, Index):
             name = data.name
-            data = data._values
+            data = data._column
             if dtype is not None:
                 data = data.astype(dtype)
         elif isinstance(data, ColumnAccessor):
@@ -4045,7 +4045,7 @@ def reverse(self):
         """
         rinds = column.arange((self._column.size - 1), -1, -1, dtype=np.int32)
         col = self._column[rinds]
-        index = self.index._values[rinds]
+        index = self.index._column[rinds]
         return self._copy_construct(data=col, index=index)
 
     def one_hot_encoding(self, cats, dtype="float64"):
diff --git a/python/cudf/cudf/tests/test_dataframe.py b/python/cudf/cudf/tests/test_dataframe.py
index 5ae678d6839..aac541d5750 100644
--- a/python/cudf/cudf/tests/test_dataframe.py
+++ b/python/cudf/cudf/tests/test_dataframe.py
@@ -1087,7 +1087,7 @@ def test_dataframe_append_to_empty():
 def test_dataframe_setitem_index_len1():
     gdf = cudf.DataFrame()
     gdf["a"] = [1]
-    gdf["b"] = gdf.index._values
+    gdf["b"] = gdf.index._column
 
     np.testing.assert_equal(gdf.b.to_array(), [0])
 
@@ -2181,12 +2181,12 @@ def query_GPU_memory(note=""):
     cudaDF = cudaDF[boolmask]
 
     assert (
-        cudaDF.index._values.data_array_view.device_ctypes_pointer
-        == cudaDF["col0"].index._values.data_array_view.device_ctypes_pointer
+        cudaDF.index._column.data_array_view.device_ctypes_pointer
+        == cudaDF["col0"].index._column.data_array_view.device_ctypes_pointer
     )
     assert (
-        cudaDF.index._values.data_array_view.device_ctypes_pointer
-        == cudaDF["col1"].index._values.data_array_view.device_ctypes_pointer
+        cudaDF.index._column.data_array_view.device_ctypes_pointer
+        == cudaDF["col1"].index._column.data_array_view.device_ctypes_pointer
     )
 
     assert memory_used == query_GPU_memory()
diff --git a/python/cudf/cudf/tests/test_index.py b/python/cudf/cudf/tests/test_index.py
index 21a431dd540..961493c6a42 100644
--- a/python/cudf/cudf/tests/test_index.py
+++ b/python/cudf/cudf/tests/test_index.py
@@ -247,13 +247,13 @@ def test_index_rename_inplace():
     # inplace=False should yield a deep copy
     gds_renamed_deep = gds.rename("new_name", inplace=False)
 
-    assert gds_renamed_deep._values.data_ptr != gds._values.data_ptr
+    assert gds_renamed_deep._column.data_ptr != gds._column.data_ptr
 
     # inplace=True returns none
-    expected_ptr = gds._values.data_ptr
+    expected_ptr = gds._column.data_ptr
     gds.rename("new_name", inplace=True)
 
-    assert expected_ptr == gds._values.data_ptr
+    assert expected_ptr == gds._column.data_ptr
 
 
 def test_index_rename_preserves_arg():
@@ -282,7 +282,7 @@ def test_set_index_as_property():
     # Check set_index(Series)
     cdf.index = cdf["b"]
 
-    assert_eq(cdf.index._values.to_array(), col2)
+    assert_eq(cdf.index._column.to_array(), col2)
 
     with pytest.raises(ValueError):
         cdf.index = [list(range(10))]
@@ -403,14 +403,14 @@ def test_index_copy_deep(idx, deep):
     same_ref = not deep
     if isinstance(idx, cudf.CategoricalIndex):
         assert (
-            idx._values.codes.base_data.ptr
-            == idx_copy._values.codes.base_data.ptr
+            idx._column.codes.base_data.ptr
+            == idx_copy._column.codes.base_data.ptr
         ) == same_ref
         if isinstance(
-            idx._values.categories, cudf.core.column.string.StringColumn
+            idx._column.categories, cudf.core.column.string.StringColumn
         ):
-            children = idx._values.categories._base_children
-            copy_children = idx_copy._values.categories._base_children
+            children = idx._column.categories._base_children
+            copy_children = idx_copy._column.categories._base_children
             assert all(
                 [
                     (
@@ -422,15 +422,15 @@ def test_index_copy_deep(idx, deep):
                 ]
             )
         elif isinstance(
-            idx._values.categories, cudf.core.column.numerical.NumericalColumn
+            idx._column.categories, cudf.core.column.numerical.NumericalColumn
         ):
             assert (
-                idx._values.categories.base_data.ptr
-                == idx_copy._values.categories.base_data.ptr
+                idx._column.categories.base_data.ptr
+                == idx_copy._column.categories.base_data.ptr
             ) == same_ref
     elif isinstance(idx, cudf.core.index.StringIndex):
-        children = idx._values._base_children
-        copy_children = idx_copy._values._base_children
+        children = idx._column._base_children
+        copy_children = idx_copy._column._base_children
         assert all(
             [
                 (
@@ -445,7 +445,7 @@ def test_index_copy_deep(idx, deep):
         )
     else:
         assert (
-            idx._values.base_data.ptr == idx_copy._values.base_data.ptr
+            idx._column.base_data.ptr == idx_copy._column.base_data.ptr
         ) == same_ref
 
 

From fa81cd45bb0eb54b2d0ebf9a118fdc6df9721e1f Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Wed, 28 Apr 2021 15:47:27 -0700
Subject: [PATCH 07/20] Move _column to FrameOneD.

---
 python/cudf/cudf/core/frame.py  | 8 ++++++++
 python/cudf/cudf/core/index.py  | 4 ----
 python/cudf/cudf/core/series.py | 8 --------
 3 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index 3dc381ac4ca..7ad5071a85e 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -3325,6 +3325,14 @@ def shape(self):
     def __iter__(self):
         cudf.utils.utils.raise_iteration_error(obj=self)
 
+    @property
+    def _column(self):
+        return self._data[self.name]
+
+    @_column.setter
+    def _column(self, value):
+        self._data[self.name] = value
+
 
 def _get_replacement_values_for_columns(
     to_replace: Any, value: Any, columns_dtype_map: Dict[Any, Any]
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index e91cb630da0..384500f4d16 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -145,10 +145,6 @@ def __init__(
         """
         pass
 
-    @property
-    def _column(self):
-        return self._data[self.name]
-
     def __getitem__(self, key):
         raise NotImplementedError()
 
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index bb04353832a..06fd6e3d6aa 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -285,14 +285,6 @@ def _from_data(
             out.name = name
         return out
 
-    @property
-    def _column(self):
-        return self._data[self.name]
-
-    @_column.setter
-    def _column(self, value):
-        self._data[self.name] = value
-
     def __contains__(self, item):
         return item in self._index
 

From 8f330c766d5e059248261247211ddc37677e0f7b Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Wed, 28 Apr 2021 16:03:27 -0700
Subject: [PATCH 08/20] Move _accessors and values.

---
 python/cudf/cudf/core/dataframe.py |  4 +---
 python/cudf/cudf/core/frame.py     | 32 ++++++++++++++++++++++++++++++
 python/cudf/cudf/core/index.py     | 24 +---------------------
 python/cudf/cudf/core/series.py    | 27 +------------------------
 4 files changed, 35 insertions(+), 52 deletions(-)

diff --git a/python/cudf/cudf/core/dataframe.py b/python/cudf/cudf/core/dataframe.py
index fc087d56b4d..e16c0fac30d 100644
--- a/python/cudf/cudf/core/dataframe.py
+++ b/python/cudf/cudf/core/dataframe.py
@@ -10,7 +10,7 @@
 import warnings
 from collections import defaultdict
 from collections.abc import Iterable, Sequence
-from typing import Any, Optional, Set, TypeVar
+from typing import Any, Optional, TypeVar
 
 import cupy
 import numpy as np
@@ -7765,8 +7765,6 @@ def explode(self, column, ignore_index=False):
 
         return super()._explode(column, ignore_index)
 
-    _accessors = set()  # type: Set[Any]
-
 
 def from_pandas(obj, nan_as_null=None):
     """
diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index 7ad5071a85e..3f5f371ac2e 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -48,6 +48,12 @@ class Frame(libcudf.table.Table):
 
     _data: "ColumnAccessor"
 
+    @classmethod
+    def __init_subclass__(cls):
+        # All subclasses contain a set _accessors that is used to hold custom
+        # accessors defined by user APIs (see cudf/api/extensions/accessor.py).
+        cls._accessors = set()
+
     @classmethod
     def _from_table(cls, table: Frame):
         return cls(table._data, index=table._index)
@@ -3333,6 +3339,32 @@ def _column(self):
     def _column(self, value):
         self._data[self.name] = value
 
+    @property
+    def values(self):
+        """
+        Return a CuPy representation of the data.
+
+        Returns
+        -------
+        out : cupy.ndarray
+            A representation of the underlying data.
+
+        Examples
+        --------
+        >>> import cudf
+        >>> ser = cudf.Series([1, -10, 100, 20])
+        >>> ser.values
+        array([  1, -10, 100,  20])
+        >>> type(ser.values)
+        <class 'cupy.core.core.ndarray'>
+        >>> index = cudf.Index([1, -10, 100, 20])
+        >>> index.values
+        array([  1, -10, 100,  20])
+        >>> type(index.values)
+        <class 'cupy.core.core.ndarray'>
+        """
+        return self._column.values
+
 
 def _get_replacement_values_for_columns(
     to_replace: Any, value: Any, columns_dtype_map: Dict[Any, Any]
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index 384500f4d16..3f73cd0e016 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -4,7 +4,7 @@
 
 import pickle
 from numbers import Number
-from typing import Any, Dict, Set, Type
+from typing import Any, Dict, Type
 
 import cupy
 import numpy as np
@@ -610,26 +610,6 @@ def argsort(self, ascending=True, **kwargs):
         indices = self._column.argsort(ascending=ascending, **kwargs)
         return cupy.asarray(indices)
 
-    @property
-    def values(self):
-        """
-        Return an array representing the data in the Index.
-
-        Returns
-        -------
-        array : A cupy array of data in the Index.
-
-        Examples
-        --------
-        >>> import cudf
-        >>> index = cudf.Index([1, -10, 100, 20])
-        >>> index.values
-        array([  1, -10, 100,  20])
-        >>> type(index.values)
-        <class 'cupy.core.core.ndarray'>
-        """
-        return self._column.values
-
     def any(self):
         """
         Return whether any elements is True in Index.
@@ -1528,8 +1508,6 @@ def _from_table(cls, table):
     def _from_data(cls, data, index=None):
         return cls._from_table(FrameOneD(data=data))
 
-    _accessors = set()  # type: Set[Any]
-
     @property
     def _constructor_expanddim(self):
         return cudf.MultiIndex
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index 06fd6e3d6aa..3fbdd8ff412 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -7,7 +7,7 @@
 from collections import abc as abc
 from numbers import Number
 from shutil import get_terminal_size
-from typing import Any, Optional, Set
+from typing import Any, Optional
 from uuid import uuid4
 
 import cupy
@@ -329,29 +329,6 @@ def from_pandas(cls, s, nan_as_null=None):
         """
         return cls(s, nan_as_null=nan_as_null)
 
-    @property
-    def values(self):
-        """
-        Return a CuPy representation of the Series.
-
-        Only the values in the Series will be returned.
-
-        Returns
-        -------
-        out : cupy.ndarray
-            The values of the Series.
-
-        Examples
-        --------
-        >>> import cudf
-        >>> ser = cudf.Series([1, -10, 100, 20])
-        >>> ser.values
-        array([  1, -10, 100,  20])
-        >>> type(ser.values)
-        <class 'cupy.core.core.ndarray'>
-        """
-        return self._column.values
-
     @property
     def values_host(self):
         """
@@ -6489,8 +6466,6 @@ def explode(self, ignore_index=False):
 
         return super()._explode(self._column_names[0], ignore_index)
 
-    _accessors = set()  # type: Set[Any]
-
 
 truediv_int_dtype_corrections = {
     "int8": "float32",

From 6f28392db8c72163cab3c3c1972521ba538f8886 Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Wed, 28 Apr 2021 16:06:10 -0700
Subject: [PATCH 09/20] Move values_host.

---
 python/cudf/cudf/core/frame.py  | 28 +++++++++++++++++++++++++++-
 python/cudf/cudf/core/index.py  | 23 -----------------------
 python/cudf/cudf/core/series.py | 23 -----------------------
 3 files changed, 27 insertions(+), 47 deletions(-)

diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index 3f5f371ac2e..5d00d4a97bf 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -3347,7 +3347,7 @@ def values(self):
         Returns
         -------
         out : cupy.ndarray
-            A representation of the underlying data.
+            A device representation of the underlying data.
 
         Examples
         --------
@@ -3365,6 +3365,32 @@ def values(self):
         """
         return self._column.values
 
+    @property
+    def values_host(self):
+        """
+        Return a NumPy representation of the data.
+
+        Returns
+        -------
+        out : numpy.ndarray
+            A host representation of the underlying data.
+
+        Examples
+        --------
+        >>> import cudf
+        >>> ser = cudf.Series([1, -10, 100, 20])
+        >>> ser.values_host
+        array([  1, -10, 100,  20])
+        >>> type(ser.values_host)
+        <class 'numpy.ndarray'>
+        >>> index = cudf.Index([1, -10, 100, 20])
+        >>> index.values_host
+        array([  1, -10, 100,  20])
+        >>> type(index.values_host)
+        <class 'numpy.ndarray'>
+        """
+        return self._column.values_host
+
 
 def _get_replacement_values_for_columns(
     to_replace: Any, value: Any, columns_dtype_map: Dict[Any, Any]
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index 3f73cd0e016..e854e2551d7 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -316,29 +316,6 @@ def to_arrow(self):
 
         return self._data.columns[0].to_arrow()
 
-    @property
-    def values_host(self):
-        """
-        Return a numpy representation of the Index.
-
-        Only the values in the Index will be returned.
-
-        Returns
-        -------
-        out : numpy.ndarray
-            The values of the Index.
-
-        Examples
-        --------
-        >>> import cudf
-        >>> index = cudf.Index([1, -10, 100, 20])
-        >>> index.values_host
-        array([  1, -10, 100,  20])
-        >>> type(index.values_host)
-        <class 'numpy.ndarray'>
-        """
-        return self._column.values_host
-
     @classmethod
     def deserialize(cls, header, frames):
         h = header["index_column"]
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index 3fbdd8ff412..cbaf1508150 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -329,29 +329,6 @@ def from_pandas(cls, s, nan_as_null=None):
         """
         return cls(s, nan_as_null=nan_as_null)
 
-    @property
-    def values_host(self):
-        """
-        Return a numpy representation of the Series.
-
-        Only the values in the Series will be returned.
-
-        Returns
-        -------
-        out : numpy.ndarray
-            The values of the Series.
-
-        Examples
-        --------
-        >>> import cudf
-        >>> ser = cudf.Series([1, -10, 100, 20])
-        >>> ser.values_host
-        array([  1, -10, 100,  20])
-        >>> type(ser.values_host)
-        <class 'numpy.ndarray'>
-        """
-        return self._column.values_host
-
     def serialize(self):
         header = {}
         frames = []

From 04f93414ba375f5ac89bc81093ddb143d38d5a50 Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Wed, 28 Apr 2021 16:42:04 -0700
Subject: [PATCH 10/20] Remove redundant copy method overrides.

---
 python/cudf/cudf/core/dataframe.py | 14 --------------
 python/cudf/cudf/core/index.py     |  2 +-
 python/cudf/cudf/core/series.py    |  8 --------
 3 files changed, 1 insertion(+), 23 deletions(-)

diff --git a/python/cudf/cudf/core/dataframe.py b/python/cudf/cudf/core/dataframe.py
index e16c0fac30d..72ccd3a78af 100644
--- a/python/cudf/cudf/core/dataframe.py
+++ b/python/cudf/cudf/core/dataframe.py
@@ -3154,20 +3154,6 @@ def take(self, positions, keep_index=True):
         out.columns = self.columns
         return out
 
-    def __copy__(self):
-        return self.copy(deep=True)
-
-    def __deepcopy__(self, memo=None):
-        """
-        Parameters
-        ----------
-        memo, default None
-            Standard signature. Unused
-        """
-        if memo is None:
-            memo = {}
-        return self.copy(deep=True)
-
     @annotate("INSERT", color="green", domain="cudf_python")
     def insert(self, loc, name, value):
         """ Add a column to DataFrame at the index specified by loc.
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index e854e2551d7..279d916997e 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -314,7 +314,7 @@ def to_arrow(self):
         ]
         """
 
-        return self._data.columns[0].to_arrow()
+        return self._column.to_arrow()
 
     @classmethod
     def deserialize(cls, header, frames):
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index cbaf1508150..6d282c95db2 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -586,14 +586,6 @@ def drop(
         if not inplace:
             return out
 
-    def __copy__(self, deep=True):
-        return self.copy(deep)
-
-    def __deepcopy__(self, memo=None):
-        if memo is None:
-            memo = {}
-        return self.copy()
-
     def append(self, to_append, ignore_index=False, verify_integrity=False):
         """Append values from another ``Series`` or array-like object.
         If ``ignore_index=True``, the index is reset.

From 8feb36bdf908a597f26b7c1f7f2ee526314f1c47 Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Wed, 28 Apr 2021 16:49:02 -0700
Subject: [PATCH 11/20] Move len.

---
 python/cudf/cudf/core/frame.py  | 3 +++
 python/cudf/cudf/core/index.py  | 3 ---
 python/cudf/cudf/core/series.py | 5 -----
 3 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index 5d00d4a97bf..875d61c5153 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -3331,6 +3331,9 @@ def shape(self):
     def __iter__(self):
         cudf.utils.utils.raise_iteration_error(obj=self)
 
+    def __len__(self):
+        return len(self._column)
+
     @property
     def _column(self):
         return self._data[self.name]
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index 279d916997e..bf9adad4e11 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -1963,9 +1963,6 @@ def copy(self, name=None, deep=False, dtype=None, names=None):
     def __sizeof__(self):
         return self._column.__sizeof__()
 
-    def __len__(self):
-        return len(self._column)
-
     def __repr__(self):
         max_seq_items = get_option("max_seq_items") or len(self)
         mr = 0
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index 6d282c95db2..b1b96642421 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -958,11 +958,6 @@ def memory_usage(self, index=True, deep=False):
             n += self._index.memory_usage(deep=deep)
         return n
 
-    def __len__(self):
-        """Returns the size of the ``Series`` including null values.
-        """
-        return len(self._column)
-
     def __array_ufunc__(self, ufunc, method, *inputs, **kwargs):
         if method == "__call__":
             return get_appropriate_dispatched_func(

From 2623c96bdb23f7ccc3c18c7920ec4218e5b22167 Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Wed, 28 Apr 2021 16:59:45 -0700
Subject: [PATCH 12/20] Move __bool__, to_gpu_array, tolist, and to_list.

---
 python/cudf/cudf/core/frame.py        | 50 +++++++++++++++++++++++++++
 python/cudf/cudf/core/index.py        | 25 --------------
 python/cudf/cudf/core/series.py       | 50 ---------------------------
 python/cudf/cudf/tests/test_index.py  |  2 +-
 python/cudf/cudf/tests/test_series.py |  2 +-
 5 files changed, 52 insertions(+), 77 deletions(-)

diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index 875d61c5153..5d1506d24df 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -3334,6 +3334,12 @@ def __iter__(self):
     def __len__(self):
         return len(self._column)
 
+    def __bool__(self):
+        raise TypeError(
+            f"The truth value of a {type(self)} is ambiguous. Use "
+            "a.empty, a.bool(), a.item(), a.any() or a.all()."
+        )
+
     @property
     def _column(self):
         return self._data[self.name]
@@ -3394,6 +3400,50 @@ def values_host(self):
         """
         return self._column.values_host
 
+    def tolist(self):
+
+        raise TypeError(
+            "cuDF does not support conversion to host memory "
+            "via the `tolist()` method. Consider using "
+            "`.to_arrow().to_pylist()` to construct a Python list."
+        )
+
+    to_list = tolist
+
+    def to_gpu_array(self, fillna=None):
+        """Get a dense numba device array for the data.
+
+        Parameters
+        ----------
+        fillna : str or None
+            See *fillna* in ``.to_array``.
+
+        Notes
+        -----
+
+        if ``fillna`` is ``None``, null values are skipped.  Therefore, the
+        output size could be smaller.
+
+        Returns
+        -------
+        numba.DeviceNDArray
+
+        Examples
+        --------
+        >>> import cudf
+        >>> s = cudf.Series([10, 20, 30, 40, 50])
+        >>> s
+        0    10
+        1    20
+        2    30
+        3    40
+        4    50
+        dtype: int64
+        >>> s.to_gpu_array()
+        <numba.cuda.cudadrv.devicearray.DeviceNDArray object at 0x7f1840858890>
+        """
+        return self._column.to_gpu_array(fillna=fillna)
+
 
 def _get_replacement_values_for_columns(
     to_replace: Any, value: Any, columns_dtype_map: Dict[Any, Any]
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index bf9adad4e11..ded7b826191 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -612,16 +612,6 @@ def to_pandas(self):
         """
         return pd.Index(self._column.to_pandas(), name=self.name)
 
-    def tolist(self):
-
-        raise TypeError(
-            "cuDF does not support conversion to host memory "
-            "via `tolist()` method. Consider using "
-            "`.to_arrow().to_pylist()` to construct a Python list."
-        )
-
-    to_list = tolist
-
     @ioutils.doc_to_dlpack()
     def to_dlpack(self):
         """{docstring}"""
@@ -1784,21 +1774,6 @@ def find_label_range(self, first=None, last=None):
     def to_frame(self, index=True, name=None):
         return _to_frame(self, index, name)
 
-    def to_gpu_array(self, fillna=None):
-        """Get a dense numba device array for the data.
-
-        Parameters
-        ----------
-        fillna : str or None
-            Replacement value to fill in place of nulls.
-
-        Notes
-        -----
-        if ``fillna`` is ``None``, null values are skipped.  Therefore, the
-        output size could be smaller.
-        """
-        return self._column.to_gpu_array(fillna=fillna)
-
     def to_pandas(self):
         return pd.RangeIndex(
             start=self._start,
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index b1b96642421..a44d5dd6b2c 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -1154,22 +1154,6 @@ def take(self, indices, keep_index=True):
             data = self._column.take(col_inds, keep_index=False)
             return self._copy_construct(data=data, index=None)
 
-    def __bool__(self):
-        """Always raise TypeError when converting a Series
-        into a boolean.
-        """
-        raise TypeError(f"can't compute boolean for {type(self)}")
-
-    def tolist(self):
-
-        raise TypeError(
-            "cuDF does not support conversion to host memory "
-            "via `tolist()` method. Consider using "
-            "`.to_arrow().to_pylist()` to construct a Python list."
-        )
-
-    to_list = tolist
-
     def head(self, n=5):
         """
         Return the first `n` rows.
@@ -3052,40 +3036,6 @@ def any(self, axis=0, bool_only=None, skipna=True, level=None, **kwargs):
 
         return result_series._column.any()
 
-    def to_gpu_array(self, fillna=None):
-        """Get a dense numba device array for the data.
-
-        Parameters
-        ----------
-        fillna : str or None
-            See *fillna* in ``.to_array``.
-
-        Notes
-        -----
-
-        if ``fillna`` is ``None``, null values are skipped.  Therefore, the
-        output size could be smaller.
-
-        Returns
-        -------
-        numba DeviceNDArray
-
-        Examples
-        --------
-        >>> import cudf
-        >>> s = cudf.Series([10, 20, 30, 40, 50])
-        >>> s
-        0    10
-        1    20
-        2    30
-        3    40
-        4    50
-        dtype: int64
-        >>> s.to_gpu_array()
-        <numba.cuda.cudadrv.devicearray.DeviceNDArray object at 0x7f1840858890>
-        """
-        return self._column.to_gpu_array(fillna=fillna)
-
     def to_pandas(self, index=True, nullable=False, **kwargs):
         """
         Convert to a Pandas Series.
diff --git a/python/cudf/cudf/tests/test_index.py b/python/cudf/cudf/tests/test_index.py
index 961493c6a42..160c72ec461 100644
--- a/python/cudf/cudf/tests/test_index.py
+++ b/python/cudf/cudf/tests/test_index.py
@@ -1799,7 +1799,7 @@ def test_index_tolist(data, dtype):
         TypeError,
         match=re.escape(
             r"cuDF does not support conversion to host memory "
-            r"via `tolist()` method. Consider using "
+            r"via the `tolist()` method. Consider using "
             r"`.to_arrow().to_pylist()` to construct a Python list."
         ),
     ):
diff --git a/python/cudf/cudf/tests/test_series.py b/python/cudf/cudf/tests/test_series.py
index 0dc53fa29e9..0cc0ad57745 100644
--- a/python/cudf/cudf/tests/test_series.py
+++ b/python/cudf/cudf/tests/test_series.py
@@ -372,7 +372,7 @@ def test_series_tolist(data):
         TypeError,
         match=re.escape(
             r"cuDF does not support conversion to host memory "
-            r"via `tolist()` method. Consider using "
+            r"via the `tolist()` method. Consider using "
             r"`.to_arrow().to_pylist()` to construct a Python list."
         ),
     ):

From a6c15f27c932834d5f6f0684effdd3ef7e3f2cea Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Thu, 29 Apr 2021 09:23:55 -0700
Subject: [PATCH 13/20] Move from_arrow.

---
 python/cudf/cudf/core/frame.py      | 31 +++++++++++++++++++++++++++++
 python/cudf/cudf/core/index.py      | 27 -------------------------
 python/cudf/cudf/core/multiindex.py |  6 +++---
 python/cudf/cudf/core/series.py     | 31 -----------------------------
 4 files changed, 34 insertions(+), 61 deletions(-)

diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index 5d1506d24df..1505155a506 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -3444,6 +3444,37 @@ def to_gpu_array(self, fillna=None):
         """
         return self._column.to_gpu_array(fillna=fillna)
 
+    @classmethod
+    def from_arrow(cls, array):
+        """Create from PyArrow Array/ChunkedArray.
+
+        Parameters
+        ----------
+        array : PyArrow Array/ChunkedArray
+            PyArrow Object which has to be converted.
+
+        Raises
+        ------
+        TypeError for invalid input type.
+
+        Returns
+        -------
+        FrameOneD
+
+        Examples
+        --------
+        >>> import cudf
+        >>> import pyarrow as pa
+        >>> cudf.Index.from_arrow(pa.array(["a", "b", None]))
+        StringIndex(['a' 'b' None], dtype='object')
+        >>> cudf.Series.from_arrow(pa.array(["a", "b", None]))
+        0       a
+        1       b
+        2    <NA>
+        dtype: object
+        """
+        return cls(cudf.core.column.column.ColumnBase.from_arrow(array))
+
 
 def _get_replacement_values_for_columns(
     to_replace: Any, value: Any, columns_dtype_map: Dict[Any, Any]
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index ded7b826191..94a28338adc 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -267,33 +267,6 @@ def get_level_values(self, level):
         else:
             raise KeyError(f"Requested level with name {level} " "not found")
 
-    @classmethod
-    def from_arrow(cls, array):
-        """Convert PyArrow Array/ChunkedArray to Index
-
-        Parameters
-        ----------
-        array : PyArrow Array/ChunkedArray
-            PyArrow Object which has to be converted to Index
-
-        Raises
-        ------
-        TypeError for invalid input type.
-
-        Returns
-        -------
-        cudf Index
-
-        Examples
-        --------
-        >>> import cudf
-        >>> import pyarrow as pa
-        >>> cudf.Index.from_arrow(pa.array(["a", "b", None]))
-        StringIndex(['a' 'b' None], dtype='object')
-        """
-
-        return cls(cudf.core.column.column.ColumnBase.from_arrow(array))
-
     def to_arrow(self):
         """Convert Index to PyArrow Array
 
diff --git a/python/cudf/cudf/core/multiindex.py b/python/cudf/cudf/core/multiindex.py
index a4748632aab..ee38e737e82 100644
--- a/python/cudf/cudf/core/multiindex.py
+++ b/python/cudf/cudf/core/multiindex.py
@@ -19,7 +19,7 @@
 from cudf.core._compat import PANDAS_GE_120
 from cudf.core.column import column
 from cudf.core.column_accessor import ColumnAccessor
-from cudf.core.frame import Frame
+from cudf.core.frame import Frame, FrameOneD
 from cudf.core.index import Index, as_index
 
 
@@ -572,7 +572,7 @@ def from_arrow(cls, table):
                    names=['a', 'b'])
         """
 
-        return super(Index, cls).from_arrow(table)
+        return super(FrameOneD, cls).from_arrow(table)
 
     def to_arrow(self):
         """Convert MultiIndex to PyArrow Table
@@ -606,7 +606,7 @@ def to_arrow(self):
         ]
         """
 
-        return super(Index, self).to_arrow()
+        return super(FrameOneD, self).to_arrow()
 
     @property
     def codes(self):
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index a44d5dd6b2c..41eaf15f271 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -411,37 +411,6 @@ def _get_columns_by_label(self, labels, downcast=False):
             else self.__class__(dtype=self.dtype, name=self.name)
         )
 
-    @classmethod
-    def from_arrow(cls, array):
-        """
-        Convert from PyArrow Array/ChunkedArray to Series.
-
-        Parameters
-        ----------
-        array : PyArrow Array/ChunkedArray
-            PyArrow Object which has to be converted to cudf Series.
-
-        Raises
-        ------
-        TypeError for invalid input type.
-
-        Returns
-        -------
-        cudf Series
-
-        Examples
-        --------
-        >>> import cudf
-        >>> import pyarrow as pa
-        >>> cudf.Series.from_arrow(pa.array(["a", "b", None]))
-        0       a
-        1       b
-        2    <NA>
-        dtype: object
-        """
-
-        return cls(cudf.core.column.ColumnBase.from_arrow(array))
-
     def to_arrow(self):
         """
         Convert Series to a PyArrow Array.

From 808d5359531e4564161e8a7e97d2cef59ad9f98a Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Thu, 29 Apr 2021 09:27:13 -0700
Subject: [PATCH 14/20] Move to_arrow.

---
 python/cudf/cudf/core/frame.py  | 30 ++++++++++++++++++++++++++++++
 python/cudf/cudf/core/index.py  | 22 ----------------------
 python/cudf/cudf/core/series.py | 22 ----------------------
 3 files changed, 30 insertions(+), 44 deletions(-)

diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index 1505155a506..20b9edfb843 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -3475,6 +3475,36 @@ def from_arrow(cls, array):
         """
         return cls(cudf.core.column.column.ColumnBase.from_arrow(array))
 
+    def to_arrow(self):
+        """
+        Convert to a PyArrow Array.
+
+        Returns
+        -------
+        PyArrow Array
+
+        Examples
+        --------
+        >>> import cudf
+        >>> sr = cudf.Series(["a", "b", None])
+        >>> sr.to_arrow()
+        <pyarrow.lib.StringArray object at 0x7f796b0e7600>
+        [
+          "a",
+          "b",
+          null
+        ]
+        >>> ind = cudf.Index(["a", "b", None])
+        >>> ind.to_arrow()
+        <pyarrow.lib.StringArray object at 0x7f796b0e7750>
+        [
+          "a",
+          "b",
+          null
+        ]
+        """
+        return self._column.to_arrow()
+
 
 def _get_replacement_values_for_columns(
     to_replace: Any, value: Any, columns_dtype_map: Dict[Any, Any]
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index 94a28338adc..25b00042efd 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -267,28 +267,6 @@ def get_level_values(self, level):
         else:
             raise KeyError(f"Requested level with name {level} " "not found")
 
-    def to_arrow(self):
-        """Convert Index to PyArrow Array
-
-        Returns
-        -------
-        PyArrow Array
-
-        Examples
-        --------
-        >>> import cudf
-        >>> ind = cudf.Index(["a", "b", None])
-        >>> ind.to_arrow()
-        <pyarrow.lib.StringArray object at 0x7f796b0e7750>
-        [
-          "a",
-          "b",
-          null
-        ]
-        """
-
-        return self._column.to_arrow()
-
     @classmethod
     def deserialize(cls, header, frames):
         h = header["index_column"]
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index 41eaf15f271..64606695c19 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -411,28 +411,6 @@ def _get_columns_by_label(self, labels, downcast=False):
             else self.__class__(dtype=self.dtype, name=self.name)
         )
 
-    def to_arrow(self):
-        """
-        Convert Series to a PyArrow Array.
-
-        Returns
-        -------
-        PyArrow Array
-
-        Examples
-        --------
-        >>> import cudf
-        >>> sr = cudf.Series(["a", "b", None])
-        >>> sr.to_arrow()
-        <pyarrow.lib.StringArray object at 0x7f796b0e7600>
-        [
-          "a",
-          "b",
-          null
-        ]
-        """
-        return self._column.to_arrow()
-
     def drop(
         self,
         labels=None,

From 7e899cdb664b5d50311feb3c5af30ff0d68db579 Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Thu, 29 Apr 2021 10:11:11 -0700
Subject: [PATCH 15/20] Clean up to_frame.

---
 python/cudf/cudf/core/index.py      | 65 +++++++++++++----------------
 python/cudf/cudf/core/multiindex.py | 26 ------------
 2 files changed, 28 insertions(+), 63 deletions(-)

diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index 25b00042efd..c70b3d04a31 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -45,34 +45,6 @@
 from cudf.utils.utils import cached_property, search_range
 
 
-def _to_frame(this_index, index=True, name=None):
-    """Create a DataFrame with a column containing this Index
-
-    Parameters
-    ----------
-    index : boolean, default True
-        Set the index of the returned DataFrame as the original Index
-    name : str, default None
-        Name to be used for the column
-
-    Returns
-    -------
-    DataFrame
-        cudf DataFrame
-    """
-
-    if name is not None:
-        col_name = name
-    elif this_index.name is None:
-        col_name = 0
-    else:
-        col_name = this_index.name
-
-    return cudf.DataFrame(
-        {col_name: this_index._column}, index=this_index if index else None
-    )
-
-
 class Index(FrameOneD, Serializable):
 
     dtype: DtypeObj
@@ -544,6 +516,33 @@ def any(self):
         """
         return self._column.any()
 
+    def to_frame(self, index=True, name=None):
+        """Create a DataFrame with a column containing this Index
+
+        Parameters
+        ----------
+        index : boolean, default True
+            Set the index of the returned DataFrame as the original Index
+        name : str, default None
+            Name to be used for the column
+
+        Returns
+        -------
+        DataFrame
+            cudf DataFrame
+        """
+
+        if name is not None:
+            col_name = name
+        elif self.name is None:
+            col_name = 0
+        else:
+            col_name = self.name
+
+        return cudf.DataFrame(
+            {col_name: self._column}, index=self if index else None
+        )
+
     def to_pandas(self):
         """
         Convert to a Pandas Index.
@@ -1680,7 +1679,7 @@ def is_contiguous(self):
 
     @property
     def size(self):
-        return self.__len__()
+        return len(self)
 
     def find_label_range(self, first=None, last=None):
         """Find subrange in the ``RangeIndex``, marked by their positions, that
@@ -1721,10 +1720,6 @@ def find_label_range(self, first=None, last=None):
 
         return begin, end
 
-    @copy_docstring(_to_frame)  # type: ignore
-    def to_frame(self, index=True, name=None):
-        return _to_frame(self, index, name)
-
     def to_pandas(self):
         return pd.RangeIndex(
             start=self._start,
@@ -1978,10 +1973,6 @@ def __getitem__(self, index):
         else:
             return res
 
-    @copy_docstring(_to_frame)  # type: ignore
-    def to_frame(self, index=True, name=None):
-        return _to_frame(self, index, name)
-
     @property
     def dtype(self):
         """
diff --git a/python/cudf/cudf/core/multiindex.py b/python/cudf/cudf/core/multiindex.py
index ee38e737e82..896de51f046 100644
--- a/python/cudf/cudf/core/multiindex.py
+++ b/python/cudf/cudf/core/multiindex.py
@@ -1048,9 +1048,6 @@ def deserialize(cls, header, frames):
         names = pickle.loads(header["names"])
         return MultiIndex(names=names, source_data=source_data)
 
-    def __iter__(self):
-        cudf.utils.utils.raise_iteration_error(obj=self)
-
     def __getitem__(self, index):
         # TODO: This should be a take of the _source_data only
         match = self.take(index)
@@ -1107,29 +1104,6 @@ def get_level_values(self, level):
         )
         return level_values
 
-    def _to_frame(self):
-
-        # for each column of codes
-        # replace column with mapping from integers to levels
-        df = self.codes.copy(deep=False)
-        for idx, col in enumerate(df.columns):
-            # use merge as a replace fn
-            level = cudf.DataFrame(
-                {
-                    "idx": column.arange(
-                        len(self.levels[idx]), dtype=df[col].dtype
-                    ),
-                    "level": self.levels[idx],
-                }
-            )
-            code = cudf.DataFrame({"idx": df[col]})
-            df[col] = code.merge(level).level
-        return df
-
-    @property
-    def _values(self):
-        return list([i for i in self])
-
     @classmethod
     def _concat(cls, objs):
 

From 85efcdbb2b4c89727731e657987ecafe46461dfe Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Thu, 29 Apr 2021 12:14:10 -0700
Subject: [PATCH 16/20] Minor improvement.

---
 python/cudf/cudf/core/series.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index 64606695c19..9ef03c7f45f 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -261,8 +261,7 @@ def __init__(
 
     @classmethod
     def _from_table(cls, table, index=None):
-        name = next(iter(table._data.keys()))
-        data = next(iter(table._data.values()))
+        name, data = next(iter(table._data.items()))
         if index is None:
             if table._index is not None:
                 index = Index._from_table(table._index)

From 1bd0e2bc57016e31d3b0112f0b3bdc595a408f1b Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Thu, 29 Apr 2021 15:48:47 -0700
Subject: [PATCH 17/20] Revert "Rename index._values to index._column."

This reverts commit 58f0a236d42ed3d10a7dccf79011dcaf2a741a55.

# Conflicts:
#	python/cudf/cudf/core/index.py
---
 python/cudf/cudf/core/column/categorical.py |  12 +-
 python/cudf/cudf/core/column/column.py      |   2 +-
 python/cudf/cudf/core/dataframe.py          |   2 +-
 python/cudf/cudf/core/frame.py              |   4 +-
 python/cudf/cudf/core/index.py              | 120 ++++++++++----------
 python/cudf/cudf/core/indexing.py           |   6 +-
 python/cudf/cudf/core/series.py             |   4 +-
 python/cudf/cudf/tests/test_dataframe.py    |  10 +-
 python/cudf/cudf/tests/test_index.py        |  30 ++---
 9 files changed, 96 insertions(+), 94 deletions(-)

diff --git a/python/cudf/cudf/core/column/categorical.py b/python/cudf/cudf/core/column/categorical.py
index 1e11138fcf0..3cd1a599ddc 100644
--- a/python/cudf/cudf/core/column/categorical.py
+++ b/python/cudf/cudf/core/column/categorical.py
@@ -918,7 +918,7 @@ def as_numerical(self) -> NumericalColumn:
 
     @property
     def categories(self) -> ColumnBase:
-        return self.dtype.categories._column
+        return self.dtype.categories._values
 
     @categories.setter
     def categories(self, value):
@@ -1044,7 +1044,7 @@ def normalize_binop_value(self, other: ScalarLike) -> CategoricalColumn:
             self._encode(other), size=len(self), dtype=self.codes.dtype
         )
         col = column.build_categorical_column(
-            categories=self.dtype.categories._column,
+            categories=self.dtype.categories._values,
             codes=column.as_column(ary),
             mask=self.base_mask,
             ordered=self.dtype.ordered,
@@ -1056,7 +1056,7 @@ def sort_by_values(
     ) -> Tuple[CategoricalColumn, NumericalColumn]:
         codes, inds = self.as_numerical.sort_by_values(ascending, na_position)
         col = column.build_categorical_column(
-            categories=self.dtype.categories._column,
+            categories=self.dtype.categories._values,
             codes=column.as_column(codes.base_data, dtype=codes.dtype),
             mask=codes.base_mask,
             size=codes.size,
@@ -1317,7 +1317,7 @@ def fillna(
         result = super().fillna(value=fill_value, method=method)
 
         result = column.build_categorical_column(
-            categories=self.dtype.categories._column,
+            categories=self.dtype.categories._values,
             codes=column.as_column(result.base_data, dtype=result.dtype),
             offset=result.offset,
             size=result.size,
@@ -1381,7 +1381,7 @@ def as_categorical_column(
         if not isinstance(dtype, CategoricalDtype):
             raise ValueError("dtype must be CategoricalDtype")
 
-        if not isinstance(self.categories, type(dtype.categories._column)):
+        if not isinstance(self.categories, type(dtype.categories._values)):
             # If both categories are of different Column types,
             # return a column full of Nulls.
             return _create_empty_categorical_column(self, dtype)
@@ -1434,7 +1434,7 @@ def copy(self, deep: bool = True) -> CategoricalColumn:
             )
         else:
             return column.build_categorical_column(
-                categories=self.dtype.categories._column,
+                categories=self.dtype.categories._values,
                 codes=column.as_column(
                     self.codes.base_data, dtype=self.codes.dtype
                 ),
diff --git a/python/cudf/cudf/core/column/column.py b/python/cudf/cudf/core/column/column.py
index 509925d7a97..0f039b137bc 100644
--- a/python/cudf/cudf/core/column/column.py
+++ b/python/cudf/cudf/core/column/column.py
@@ -1802,7 +1802,7 @@ def as_column(
         if dtype is not None:
             data = data.astype(dtype)
     elif isinstance(arbitrary, cudf.Index):
-        data = arbitrary._column
+        data = arbitrary._values
         if dtype is not None:
             data = data.astype(dtype)
 
diff --git a/python/cudf/cudf/core/dataframe.py b/python/cudf/cudf/core/dataframe.py
index 72ccd3a78af..e5d582fce42 100644
--- a/python/cudf/cudf/core/dataframe.py
+++ b/python/cudf/cudf/core/dataframe.py
@@ -7985,7 +7985,7 @@ def _get_union_of_indices(indexes):
     else:
         merged_index = cudf.core.Index._concat(indexes)
         merged_index = merged_index.drop_duplicates()
-        _, inds = merged_index._column.sort_by_values()
+        _, inds = merged_index._values.sort_by_values()
         return merged_index.take(inds)
 
 
diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index 20b9edfb843..c51d1a80890 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -481,9 +481,9 @@ def _concat(
             )
             if not isinstance(
                 out._index, cudf.MultiIndex
-            ) and is_categorical_dtype(out._index._column.dtype):
+            ) and is_categorical_dtype(out._index._values.dtype):
                 out = out.set_index(
-                    cudf.core.index.as_index(out.index._column)
+                    cudf.core.index.as_index(out.index._values)
                 )
 
         # Reassign index and column names
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index c70b3d04a31..5681f824faf 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -117,6 +117,10 @@ def __init__(
         """
         pass
 
+    @cached_property
+    def _values(self) -> ColumnBase:
+        raise NotImplementedError
+
     def __getitem__(self, key):
         raise NotImplementedError()
 
@@ -153,7 +157,7 @@ def serialize(self):
         header["index_column"] = {}
         # store metadata values of index separately
         # Indexes: Numerical/DateTime/String are often GPU backed
-        header["index_column"], frames = self._column.serialize()
+        header["index_column"], frames = self._values.serialize()
 
         header["name"] = pickle.dumps(self.name)
         header["dtype"] = pickle.dumps(self.dtype)
@@ -162,7 +166,7 @@ def serialize(self):
         return header, frames
 
     def __contains__(self, item):
-        return item in self._column
+        return item in self._values
 
     @annotate("INDEX_EQUALS", color="green", domain="cudf_python")
     def equals(self, other, **kwargs):
@@ -324,9 +328,9 @@ def _clean_nulls_from_index(self):
         methods using this method to replace or handle representation
         of the actual types correctly.
         """
-        if self._column.has_nulls:
+        if self._values.has_nulls:
             return cudf.Index(
-                self._column.astype("str").fillna(cudf._NA_REP), name=self.name
+                self._values.astype("str").fillna(cudf._NA_REP), name=self.name
             )
         else:
             return self
@@ -507,15 +511,9 @@ def argsort(self, ascending=True, **kwargs):
         >>> index.argsort(ascending=False)
         array([3, 2, 1, 0, 4], dtype=int32)
         """
-        indices = self._column.argsort(ascending=ascending, **kwargs)
+        indices = self._values.argsort(ascending=ascending, **kwargs)
         return cupy.asarray(indices)
 
-    def any(self):
-        """
-        Return whether any elements is True in Index.
-        """
-        return self._column.any()
-
     def to_frame(self, index=True, name=None):
         """Create a DataFrame with a column containing this Index
 
@@ -540,7 +538,7 @@ def to_frame(self, index=True, name=None):
             col_name = self.name
 
         return cudf.DataFrame(
-            {col_name: self._column}, index=self if index else None
+            {col_name: self._values}, index=self if index else None
         )
 
     def to_pandas(self):
@@ -560,7 +558,7 @@ def to_pandas(self):
         >>> type(idx)
         <class 'cudf.core.index.GenericIndex'>
         """
-        return pd.Index(self._column.to_pandas(), name=self.name)
+        return pd.Index(self._values.to_pandas(), name=self.name)
 
     @ioutils.doc_to_dlpack()
     def to_dlpack(self):
@@ -573,7 +571,7 @@ def gpu_values(self):
         """
         View the data as a numba device array object
         """
-        return self._column.data_array_view
+        return self._values.data_array_view
 
     def min(self):
         """
@@ -598,7 +596,7 @@ def min(self):
         >>> idx.min()
         1
         """
-        return self._column.min()
+        return self._values.min()
 
     def max(self):
         """
@@ -623,7 +621,7 @@ def max(self):
         >>> idx.max()
         3
         """
-        return self._column.max()
+        return self._values.max()
 
     def sum(self):
         """
@@ -641,11 +639,11 @@ def sum(self):
         >>> idx.sum()
         6
         """
-        return self._column.sum()
+        return self._values.sum()
 
     @classmethod
     def _concat(cls, objs):
-        data = ColumnBase._concat([o._column for o in objs])
+        data = ColumnBase._concat([o._values for o in objs])
         names = {obj.name for obj in objs}
         if len(names) == 1:
             [name] = names
@@ -713,7 +711,7 @@ def append(self, other):
                         f"either one of them to same dtypes."
                     )
 
-                if isinstance(self._column, cudf.core.column.NumericalColumn):
+                if isinstance(self._values, cudf.core.column.NumericalColumn):
                     if self.dtype != other.dtype:
                         this, other = numeric_normalize_types(self, other)
                 to_concat = [this, other]
@@ -867,7 +865,7 @@ def sort_values(self, return_indexer=False, ascending=True, key=None):
         if key is not None:
             raise NotImplementedError("key parameter is not yet implemented.")
 
-        indices = self._column.argsort(ascending=ascending)
+        indices = self._values.argsort(ascending=ascending)
         index_sorted = as_index(self.take(indices), name=self.name)
 
         if return_indexer:
@@ -883,7 +881,7 @@ def unique(self):
         -------
         Index without duplicates
         """
-        return as_index(self._column.unique(), name=self.name)
+        return as_index(self._values.unique(), name=self.name)
 
     def __add__(self, other):
         return self._apply_op("__add__", other)
@@ -1112,7 +1110,7 @@ def astype(self, dtype, copy=False):
             return self.copy(deep=copy)
 
         return as_index(
-            self.copy(deep=copy)._column.astype(dtype), name=self.name
+            self.copy(deep=copy)._values.astype(dtype), name=self.name
         )
 
     def to_array(self, fillna=None):
@@ -1131,7 +1129,7 @@ def to_array(self, fillna=None):
         if ``fillna`` is ``None``, null values are skipped.  Therefore, the
         output size could be smaller.
         """
-        return self._column.to_array(fillna=fillna)
+        return self._values.to_array(fillna=fillna)
 
     def to_series(self, index=None, name=None):
         """
@@ -1153,7 +1151,7 @@ def to_series(self, index=None, name=None):
         """
 
         return cudf.Series(
-            self._column,
+            self._values,
             index=self.copy(deep=False) if index is None else index,
             name=self.name if name is None else name,
         )
@@ -1178,7 +1176,7 @@ def is_monotonic_increasing(self):
         Return if the index is monotonic increasing
         (only equal or increasing) values.
         """
-        return self._column.is_monotonic_increasing
+        return self._values.is_monotonic_increasing
 
     @property
     def is_monotonic_decreasing(self):
@@ -1186,7 +1184,7 @@ def is_monotonic_decreasing(self):
         Return if the index is monotonic decreasing
         (only equal or decreasing) values.
         """
-        return self._column.is_monotonic_decreasing
+        return self._values.is_monotonic_decreasing
 
     @property
     def empty(self):
@@ -1345,7 +1343,7 @@ def memory_usage(self, deep=False):
         -------
             bytes used
         """
-        return self._column._memory_usage(deep=deep)
+        return self._values._memory_usage(deep=deep)
 
     @classmethod
     def from_pandas(cls, index, nan_as_null=None):
@@ -1527,7 +1525,7 @@ def _num_rows(self):
         return len(self)
 
     @cached_property
-    def _column(self):
+    def _values(self):
         if len(self) > 0:
             return column.arange(
                 self._start, self._stop, self._step, dtype=self.dtype
@@ -1538,7 +1536,7 @@ def _column(self):
     @property
     def _data(self):
         return cudf.core.column_accessor.ColumnAccessor(
-            {self.name: self._column}
+            {self.name: self._values}
         )
 
     def __contains__(self, item):
@@ -1620,7 +1618,7 @@ def __getitem__(self, index):
                 index = np.min_scalar_type(index).type(index)
             index = column.as_column(index)
 
-        return as_index(self._column[index], name=self.name)
+        return as_index(self._values[index], name=self.name)
 
     def __eq__(self, other):
         return super(type(self), self).__eq__(other)
@@ -1788,7 +1786,7 @@ def get_slice_bound(self, label, side, kind=None):
 
     @property
     def __cuda_array_interface__(self):
-        return self._column.__cuda_array_interface__
+        return self._values.__cuda_array_interface__
 
     def memory_usage(self, **kwargs):
         return 0
@@ -1808,7 +1806,7 @@ class GenericIndex(Index):
 
     Attributes
     ----------
-    _column: A Column object
+    _values: A Column object
     name: A string
     """
 
@@ -1849,6 +1847,10 @@ def _initialize(self, values, **kwargs):
         name = kwargs.get("name")
         super(Index, self).__init__({name: values})
 
+    @property
+    def _values(self):
+        return next(iter(self._data.columns))
+
     def copy(self, name=None, deep=False, dtype=None, names=None):
         """
         Make a copy of this object.
@@ -1874,15 +1876,15 @@ def copy(self, name=None, deep=False, dtype=None, names=None):
         name = self.name if name is None else name
 
         if isinstance(self, (StringIndex, CategoricalIndex)):
-            result = as_index(self._column.astype(dtype), name=name, copy=deep)
+            result = as_index(self._values.astype(dtype), name=name, copy=deep)
         else:
             result = as_index(
-                self._column.copy(deep=deep).astype(dtype), name=name
+                self._values.copy(deep=deep).astype(dtype), name=name
             )
         return result
 
     def __sizeof__(self):
-        return self._column.__sizeof__()
+        return self._values.__sizeof__()
 
     def __repr__(self):
         max_seq_items = get_option("max_seq_items") or len(self)
@@ -1924,7 +1926,7 @@ def __repr__(self):
                 output = preprocess.to_pandas().__repr__()
 
             output = output.replace("nan", cudf._NA_REP)
-        elif preprocess._column.nullable:
+        elif preprocess._values.nullable:
             output = self._clean_nulls_from_index().to_pandas().__repr__()
 
             if not isinstance(self, StringIndex):
@@ -1965,7 +1967,7 @@ def __getitem__(self, index):
             raise NotImplementedError(
                 "Getting a scalar from an IntervalIndex is not yet supported"
             )
-        res = self._column[index]
+        res = self._values[index]
         if not isinstance(index, int):
             res = as_index(res)
             res.name = self.name
@@ -1978,7 +1980,7 @@ def dtype(self):
         """
         `dtype` of the underlying values in GenericIndex.
         """
-        return self._column.dtype
+        return self._values.dtype
 
     def find_label_range(self, first, last):
         """Find range that starts with *first* and ends with *last*,
@@ -1990,7 +1992,7 @@ def find_label_range(self, first, last):
             The starting index and the ending index.
             The *last* value occurs at ``end - 1`` position.
         """
-        col = self._column
+        col = self._values
         begin, end = None, None
         if first is not None:
             begin = col.find_first_value(first, closest=True)
@@ -2004,14 +2006,14 @@ def is_unique(self):
         """
         Return if the index has unique values.
         """
-        return self._column.is_unique
+        return self._values.is_unique
 
     def get_slice_bound(self, label, side, kind):
-        return self._column.get_slice_bound(label, side, kind)
+        return self._values.get_slice_bound(label, side, kind)
 
     @property
     def __cuda_array_interface__(self):
-        return self._column.__cuda_array_interface__
+        return self._values.__cuda_array_interface__
 
 
 class NumericIndex(GenericIndex):
@@ -2343,11 +2345,11 @@ def dayofweek(self):
         return self._get_dt_field("weekday")
 
     def to_pandas(self):
-        nanos = self._column.astype("datetime64[ns]")
+        nanos = self._values.astype("datetime64[ns]")
         return pd.DatetimeIndex(nanos.to_pandas(), name=self.name)
 
     def _get_dt_field(self, field):
-        out_column = self._column.get_dt_field(field)
+        out_column = self._values.get_dt_field(field)
         # column.column_empty_like always returns a Column object
         # but we need a NumericalColumn for GenericIndex..
         # how should this be handled?
@@ -2437,9 +2439,9 @@ def __new__(
 
     def to_pandas(self):
         return pd.TimedeltaIndex(
-            self._column.to_pandas(),
+            self._values.to_pandas(),
             name=self.name,
-            unit=self._column.time_unit,
+            unit=self._values.time_unit,
         )
 
     @property
@@ -2447,21 +2449,21 @@ def days(self):
         """
         Number of days for each element.
         """
-        return as_index(arbitrary=self._column.days, name=self.name)
+        return as_index(arbitrary=self._values.days, name=self.name)
 
     @property
     def seconds(self):
         """
         Number of seconds (>= 0 and less than 1 day) for each element.
         """
-        return as_index(arbitrary=self._column.seconds, name=self.name)
+        return as_index(arbitrary=self._values.seconds, name=self.name)
 
     @property
     def microseconds(self):
         """
         Number of microseconds (>= 0 and less than 1 second) for each element.
         """
-        return as_index(arbitrary=self._column.microseconds, name=self.name)
+        return as_index(arbitrary=self._values.microseconds, name=self.name)
 
     @property
     def nanoseconds(self):
@@ -2469,7 +2471,7 @@ def nanoseconds(self):
         Number of nanoseconds (>= 0 and less than 1 microsecond) for each
         element.
         """
-        return as_index(arbitrary=self._column.nanoseconds, name=self.name)
+        return as_index(arbitrary=self._values.nanoseconds, name=self.name)
 
     @property
     def components(self):
@@ -2477,7 +2479,7 @@ def components(self):
         Return a dataframe of the components (days, hours, minutes,
         seconds, milliseconds, microseconds, nanoseconds) of the Timedeltas.
         """
-        return self._column.components()
+        return self._values.components()
 
     @property
     def inferred_freq(self):
@@ -2593,14 +2595,14 @@ def codes(self):
         """
         The category codes of this categorical.
         """
-        return self._column.cat().codes
+        return self._values.cat().codes
 
     @property
     def categories(self):
         """
         The categories of this categorical.
         """
-        return self._column.cat().categories
+        return self._values.cat().categories
 
 
 def interval_range(
@@ -2838,7 +2840,7 @@ class StringIndex(GenericIndex):
 
     Attributes
     ----------
-    _column: A StringColumn object or NDArray of strings
+    _values: A StringColumn object or NDArray of strings
     name: A string
     """
 
@@ -2848,7 +2850,7 @@ def __new__(cls, values, copy=False, **kwargs):
         if isinstance(values, StringColumn):
             values = values.copy(deep=copy)
         elif isinstance(values, StringIndex):
-            values = values._column.copy(deep=copy)
+            values = values._values.copy(deep=copy)
         else:
             values = column.as_column(values, dtype="str")
             if not pd.api.types.is_string_dtype(values.dtype):
@@ -2863,11 +2865,11 @@ def to_pandas(self):
         return pd.Index(self.to_array(), name=self.name, dtype="object")
 
     def take(self, indices):
-        return self._column[indices]
+        return self._values[indices]
 
     def __repr__(self):
         return (
-            f"{self.__class__.__name__}({self._column.to_array()},"
+            f"{self.__class__.__name__}({self._values.to_array()},"
             f" dtype='object'"
             + (
                 f", name={pd.io.formats.printing.default_pprint(self.name)}"
@@ -2880,14 +2882,14 @@ def __repr__(self):
     @copy_docstring(StringMethods.__init__)  # type: ignore
     @property
     def str(self):
-        return StringMethods(column=self._column, parent=self)
+        return StringMethods(column=self._values, parent=self)
 
     def _clean_nulls_from_index(self):
         """
         Convert all na values(if any) in Index object
         to `<NA>` as a preprocessing step to `__repr__` methods.
         """
-        if self._column.has_nulls:
+        if self._values.has_nulls:
             return self.fillna(cudf._NA_REP)
         else:
             return self
diff --git a/python/cudf/cudf/core/indexing.py b/python/cudf/cudf/core/indexing.py
index 42d309d7054..7970b9fa3dc 100755
--- a/python/cudf/cudf/core/indexing.py
+++ b/python/cudf/cudf/core/indexing.py
@@ -30,7 +30,7 @@ def indices_from_labels(obj, labels):
 
         if is_categorical_dtype(obj.index):
             labels = labels.astype("category")
-            codes = labels.codes.astype(obj.index._column.codes.dtype)
+            codes = labels.codes.astype(obj.index._values.codes.dtype)
             labels = column.build_categorical_column(
                 categories=labels.dtype.categories,
                 codes=codes,
@@ -154,7 +154,7 @@ def __setitem__(self, key, value):
                 and not isinstance(self._sr.index, cudf.MultiIndex)
                 and is_scalar(value)
             ):
-                _append_new_row_inplace(self._sr.index._column, key)
+                _append_new_row_inplace(self._sr.index._values, key)
                 _append_new_row_inplace(self._sr._column, value)
                 return
             else:
@@ -177,7 +177,7 @@ def _loc_to_iloc(self, arg):
                     found_index = arg
                     return found_index
             try:
-                found_index = self._sr.index._column.find_first_value(
+                found_index = self._sr.index._values.find_first_value(
                     arg, closest=False
                 )
                 return found_index
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index 9ef03c7f45f..0a7fe8b69d9 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -217,7 +217,7 @@ def __init__(
             data = data.values
         elif isinstance(data, Index):
             name = data.name
-            data = data._column
+            data = data._values
             if dtype is not None:
                 data = data.astype(dtype)
         elif isinstance(data, ColumnAccessor):
@@ -3874,7 +3874,7 @@ def reverse(self):
         """
         rinds = column.arange((self._column.size - 1), -1, -1, dtype=np.int32)
         col = self._column[rinds]
-        index = self.index._column[rinds]
+        index = self.index._values[rinds]
         return self._copy_construct(data=col, index=index)
 
     def one_hot_encoding(self, cats, dtype="float64"):
diff --git a/python/cudf/cudf/tests/test_dataframe.py b/python/cudf/cudf/tests/test_dataframe.py
index aac541d5750..5ae678d6839 100644
--- a/python/cudf/cudf/tests/test_dataframe.py
+++ b/python/cudf/cudf/tests/test_dataframe.py
@@ -1087,7 +1087,7 @@ def test_dataframe_append_to_empty():
 def test_dataframe_setitem_index_len1():
     gdf = cudf.DataFrame()
     gdf["a"] = [1]
-    gdf["b"] = gdf.index._column
+    gdf["b"] = gdf.index._values
 
     np.testing.assert_equal(gdf.b.to_array(), [0])
 
@@ -2181,12 +2181,12 @@ def query_GPU_memory(note=""):
     cudaDF = cudaDF[boolmask]
 
     assert (
-        cudaDF.index._column.data_array_view.device_ctypes_pointer
-        == cudaDF["col0"].index._column.data_array_view.device_ctypes_pointer
+        cudaDF.index._values.data_array_view.device_ctypes_pointer
+        == cudaDF["col0"].index._values.data_array_view.device_ctypes_pointer
     )
     assert (
-        cudaDF.index._column.data_array_view.device_ctypes_pointer
-        == cudaDF["col1"].index._column.data_array_view.device_ctypes_pointer
+        cudaDF.index._values.data_array_view.device_ctypes_pointer
+        == cudaDF["col1"].index._values.data_array_view.device_ctypes_pointer
     )
 
     assert memory_used == query_GPU_memory()
diff --git a/python/cudf/cudf/tests/test_index.py b/python/cudf/cudf/tests/test_index.py
index 160c72ec461..158dffc3884 100644
--- a/python/cudf/cudf/tests/test_index.py
+++ b/python/cudf/cudf/tests/test_index.py
@@ -247,13 +247,13 @@ def test_index_rename_inplace():
     # inplace=False should yield a deep copy
     gds_renamed_deep = gds.rename("new_name", inplace=False)
 
-    assert gds_renamed_deep._column.data_ptr != gds._column.data_ptr
+    assert gds_renamed_deep._values.data_ptr != gds._values.data_ptr
 
     # inplace=True returns none
-    expected_ptr = gds._column.data_ptr
+    expected_ptr = gds._values.data_ptr
     gds.rename("new_name", inplace=True)
 
-    assert expected_ptr == gds._column.data_ptr
+    assert expected_ptr == gds._values.data_ptr
 
 
 def test_index_rename_preserves_arg():
@@ -282,7 +282,7 @@ def test_set_index_as_property():
     # Check set_index(Series)
     cdf.index = cdf["b"]
 
-    assert_eq(cdf.index._column.to_array(), col2)
+    assert_eq(cdf.index._values.to_array(), col2)
 
     with pytest.raises(ValueError):
         cdf.index = [list(range(10))]
@@ -403,14 +403,14 @@ def test_index_copy_deep(idx, deep):
     same_ref = not deep
     if isinstance(idx, cudf.CategoricalIndex):
         assert (
-            idx._column.codes.base_data.ptr
-            == idx_copy._column.codes.base_data.ptr
+            idx._values.codes.base_data.ptr
+            == idx_copy._values.codes.base_data.ptr
         ) == same_ref
         if isinstance(
-            idx._column.categories, cudf.core.column.string.StringColumn
+            idx._values.categories, cudf.core.column.string.StringColumn
         ):
-            children = idx._column.categories._base_children
-            copy_children = idx_copy._column.categories._base_children
+            children = idx._values.categories._base_children
+            copy_children = idx_copy._values.categories._base_children
             assert all(
                 [
                     (
@@ -422,15 +422,15 @@ def test_index_copy_deep(idx, deep):
                 ]
             )
         elif isinstance(
-            idx._column.categories, cudf.core.column.numerical.NumericalColumn
+            idx._values.categories, cudf.core.column.numerical.NumericalColumn
         ):
             assert (
-                idx._column.categories.base_data.ptr
-                == idx_copy._column.categories.base_data.ptr
+                idx._values.categories.base_data.ptr
+                == idx_copy._values.categories.base_data.ptr
             ) == same_ref
     elif isinstance(idx, cudf.core.index.StringIndex):
-        children = idx._column._base_children
-        copy_children = idx_copy._column._base_children
+        children = idx._values._base_children
+        copy_children = idx_copy._values._base_children
         assert all(
             [
                 (
@@ -445,7 +445,7 @@ def test_index_copy_deep(idx, deep):
         )
     else:
         assert (
-            idx._column.base_data.ptr == idx_copy._column.base_data.ptr
+            idx._values.base_data.ptr == idx_copy._values.base_data.ptr
         ) == same_ref
 
 

From d189984336df2c0ee8a41cd40e5bde1ff5f9d940 Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Fri, 30 Apr 2021 13:02:21 -0700
Subject: [PATCH 18/20] Fix previously incorrect usage of indexes as booleans.

---
 python/cudf/cudf/core/index.py          | 6 ++++++
 python/cudf/cudf/core/indexing.py       | 5 ++++-
 python/cudf/cudf/tests/test_pickling.py | 4 +++-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index 5681f824faf..d82b4f53e20 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -541,6 +541,12 @@ def to_frame(self, index=True, name=None):
             {col_name: self._values}, index=self if index else None
         )
 
+    def any(self):
+        """
+        Return whether any elements is True in Index.
+        """
+        return self._values.any()
+
     def to_pandas(self):
         """
         Convert to a Pandas Index.
diff --git a/python/cudf/cudf/core/indexing.py b/python/cudf/cudf/core/indexing.py
index 7970b9fa3dc..a732abc0705 100755
--- a/python/cudf/cudf/core/indexing.py
+++ b/python/cudf/cudf/core/indexing.py
@@ -2,6 +2,7 @@
 
 from typing import Any, Union
 
+import cupy as cp
 import numpy as np
 import pandas as pd
 from nvtx import annotate
@@ -58,7 +59,9 @@ def get_label_range_or_mask(index, start, stop, step):
         if start is not None and stop is not None:
             if start > stop:
                 return slice(0, 0, None)
-            boolean_mask = (index >= start) and (index <= stop)
+            # TODO: Once Index binary ops are updated to support logical_and,
+            # can use that instead of using cupy.
+            boolean_mask = cp.logical_and((index >= start), (index <= stop))
         elif start is not None:
             boolean_mask = index >= start
         else:
diff --git a/python/cudf/cudf/tests/test_pickling.py b/python/cudf/cudf/tests/test_pickling.py
index e87ab3730dd..ca819c7f59b 100644
--- a/python/cudf/cudf/tests/test_pickling.py
+++ b/python/cudf/cudf/tests/test_pickling.py
@@ -90,7 +90,9 @@ def test_pickle_index():
     idx = GenericIndex(np.arange(nelem), name="a")
     pickled = pickle.dumps(idx)
     out = pickle.loads(pickled)
-    assert idx == out
+    # TODO: Once operations like `all` are supported on Index objects, we can
+    # just use that without calling values first.
+    assert (idx == out).values.all()
 
 
 def test_pickle_buffer():

From 31ebbdbc5605a438d708a55052d4a7dca1475763 Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Fri, 30 Apr 2021 16:12:34 -0700
Subject: [PATCH 19/20] Reintroduce _constructor properties for dask.

---
 python/cudf/cudf/core/dataframe.py | 5 +++++
 python/cudf/cudf/core/series.py    | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/python/cudf/cudf/core/dataframe.py b/python/cudf/cudf/core/dataframe.py
index e5d582fce42..f2be0e3bd6e 100644
--- a/python/cudf/cudf/core/dataframe.py
+++ b/python/cudf/cudf/core/dataframe.py
@@ -554,6 +554,11 @@ def _align_input_series_indices(data, index):
 
         return data, index
 
+    # The `constructor*` properties are used by `dask` (and `dask_cudf`)
+    @property
+    def _constructor(self):
+        return DataFrame
+
     @property
     def _constructor_sliced(self):
         return Series
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index 0a7fe8b69d9..74cb3363295 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -62,6 +62,11 @@
 
 
 class Series(FrameOneD, Serializable):
+    # The `constructor*` properties are used by `dask` (and `dask_cudf`)
+    @property
+    def _constructor(self):
+        return Series
+
     @property
     def _constructor_sliced(self):
         raise NotImplementedError(

From 6c2ee13560267557daab72ee3e8dfaac7ae95496 Mon Sep 17 00:00:00 2001
From: Vyas Ramasubramani <vyasr@nvidia.com>
Date: Mon, 3 May 2021 08:42:03 -0700
Subject: [PATCH 20/20] Rename FrameOneD to SingleColumnFrame.

---
 python/cudf/cudf/core/frame.py      |  6 +++---
 python/cudf/cudf/core/index.py      | 22 +++++++++++-----------
 python/cudf/cudf/core/multiindex.py |  6 +++---
 python/cudf/cudf/core/series.py     |  8 ++++----
 4 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index c51d1a80890..4a434be42ce 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -3301,10 +3301,10 @@ def _reindex(
         return self._mimic_inplace(result, inplace=inplace)
 
 
-class FrameOneD(Frame):
+class SingleColumnFrame(Frame):
     """A one-dimensional frame.
 
-    Frames with only a single dimension share certain logic that is encoded in
+    Frames with only a single column share certain logic that is encoded in
     this class.
     """
 
@@ -3459,7 +3459,7 @@ def from_arrow(cls, array):
 
         Returns
         -------
-        FrameOneD
+        SingleColumnFrame
 
         Examples
         --------
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index d82b4f53e20..5f390be79e2 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -29,7 +29,7 @@
 )
 from cudf.core.column.string import StringMethods as StringMethods
 from cudf.core.dtypes import IntervalDtype
-from cudf.core.frame import FrameOneD
+from cudf.core.frame import SingleColumnFrame
 from cudf.utils import ioutils
 from cudf.utils.docutils import copy_docstring
 from cudf.utils.dtypes import (
@@ -45,7 +45,7 @@
 from cudf.utils.utils import cached_property, search_range
 
 
-class Index(FrameOneD, Serializable):
+class Index(SingleColumnFrame, Serializable):
 
     dtype: DtypeObj
 
@@ -1427,7 +1427,7 @@ def _from_table(cls, table):
 
     @classmethod
     def _from_data(cls, data, index=None):
-        return cls._from_table(FrameOneD(data=data))
+        return cls._from_table(SingleColumnFrame(data=data))
 
     @property
     def _constructor_expanddim(self):
@@ -1474,7 +1474,7 @@ def __new__(
         if step == 0:
             raise ValueError("Step must not be zero.")
 
-        out = FrameOneD.__new__(cls)
+        out = SingleColumnFrame.__new__(cls)
         if isinstance(start, range):
             therange = start
             start = therange.start
@@ -1827,7 +1827,7 @@ def __new__(cls, values, **kwargs):
             Column's name. Otherwise if this name is different from the value
             Column's, the values Column will be cloned to adopt this name.
         """
-        out = FrameOneD.__new__(cls)
+        out = SingleColumnFrame.__new__(cls)
         out._initialize(values, **kwargs)
 
         return out
@@ -2043,7 +2043,7 @@ class NumericIndex(GenericIndex):
 
     def __new__(cls, data=None, dtype=None, copy=False, name=None):
 
-        out = FrameOneD.__new__(cls)
+        out = SingleColumnFrame.__new__(cls)
         dtype = _index_to_dtype[cls]
         if copy:
             data = column.as_column(data, dtype=dtype).copy()
@@ -2165,7 +2165,7 @@ def __new__(
         # pandas dtindex creation first which.  For now
         # just make sure we handle np.datetime64 arrays
         # and then just dispatch upstream
-        out = FrameOneD.__new__(cls)
+        out = SingleColumnFrame.__new__(cls)
 
         if freq is not None:
             raise NotImplementedError("Freq is not yet supported")
@@ -2420,7 +2420,7 @@ def __new__(
         name=None,
     ) -> "TimedeltaIndex":
 
-        out = FrameOneD.__new__(cls)
+        out = SingleColumnFrame.__new__(cls)
 
         if freq is not None:
             raise NotImplementedError("freq is not yet supported")
@@ -2552,7 +2552,7 @@ def __new__(
                 )
         if copy:
             data = column.as_column(data, dtype=dtype).copy(deep=True)
-        out = FrameOneD.__new__(cls)
+        out = SingleColumnFrame.__new__(cls)
         kwargs = _setdefault_name(data, name=name)
         if isinstance(data, CategoricalColumn):
             data = data
@@ -2778,7 +2778,7 @@ def __new__(
     ) -> "IntervalIndex":
         if copy:
             data = column.as_column(data, dtype=dtype).copy()
-        out = FrameOneD.__new__(cls)
+        out = SingleColumnFrame.__new__(cls)
         kwargs = _setdefault_name(data, name=name)
         if isinstance(data, IntervalColumn):
             data = data
@@ -2851,7 +2851,7 @@ class StringIndex(GenericIndex):
     """
 
     def __new__(cls, values, copy=False, **kwargs):
-        out = FrameOneD.__new__(cls)
+        out = SingleColumnFrame.__new__(cls)
         kwargs = _setdefault_name(values, **kwargs)
         if isinstance(values, StringColumn):
             values = values.copy(deep=copy)
diff --git a/python/cudf/cudf/core/multiindex.py b/python/cudf/cudf/core/multiindex.py
index 896de51f046..ca029198e52 100644
--- a/python/cudf/cudf/core/multiindex.py
+++ b/python/cudf/cudf/core/multiindex.py
@@ -19,7 +19,7 @@
 from cudf.core._compat import PANDAS_GE_120
 from cudf.core.column import column
 from cudf.core.column_accessor import ColumnAccessor
-from cudf.core.frame import Frame, FrameOneD
+from cudf.core.frame import Frame, SingleColumnFrame
 from cudf.core.index import Index, as_index
 
 
@@ -572,7 +572,7 @@ def from_arrow(cls, table):
                    names=['a', 'b'])
         """
 
-        return super(FrameOneD, cls).from_arrow(table)
+        return super(SingleColumnFrame, cls).from_arrow(table)
 
     def to_arrow(self):
         """Convert MultiIndex to PyArrow Table
@@ -606,7 +606,7 @@ def to_arrow(self):
         ]
         """
 
-        return super(FrameOneD, self).to_arrow()
+        return super(SingleColumnFrame, self).to_arrow()
 
     @property
     def codes(self):
diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index 74cb3363295..5ee40d576b6 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -38,7 +38,7 @@
 from cudf.core.column.string import StringMethods
 from cudf.core.column.struct import StructMethods
 from cudf.core.column_accessor import ColumnAccessor
-from cudf.core.frame import FrameOneD, _drop_rows_by_labels
+from cudf.core.frame import SingleColumnFrame, _drop_rows_by_labels
 from cudf.core.groupby.groupby import SeriesGroupBy
 from cudf.core.index import Index, RangeIndex, as_index
 from cudf.core.indexing import _SeriesIlocIndexer, _SeriesLocIndexer
@@ -61,7 +61,7 @@
 )
 
 
-class Series(FrameOneD, Serializable):
+class Series(SingleColumnFrame, Serializable):
     # The `constructor*` properties are used by `dask` (and `dask_cudf`)
     @property
     def _constructor(self):
@@ -1043,9 +1043,9 @@ def __getitem__(self, arg):
         else:
             return self.loc[arg]
 
-    iteritems = FrameOneD.__iter__
+    iteritems = SingleColumnFrame.__iter__
 
-    items = FrameOneD.__iter__
+    items = SingleColumnFrame.__iter__
 
     def to_dict(self, into=dict):
         raise TypeError(