Make (Indexed)Frame.__init__ require data (and index) (#16430)

This PR makes `data` and `Index` required arguments of `Frame` and `IndexedFrame` where relevant so we can gradually move towards ensuring `data` and `index` are valid mapping of columns and a cudf Index respectively

Authors:
  - Matthew Roeschke (https://github.com/mroeschke)

Approvers:
  - Vyas Ramasubramani (https://github.com/vyasr)

URL: #16430

python/cudf/cudf/core/dataframe.py

@@ -697,7 +697,7 @@ def __init__(
     ):
         if copy is not None:
             raise NotImplementedError("copy is not currently implemented.")
-        super().__init__()
+        super().__init__({}, index=cudf.Index([]))
         if nan_as_null is no_default:
             nan_as_null = not cudf.get_option("mode.pandas_compatible")
 

python/cudf/cudf/core/frame.py

@@ -53,14 +53,10 @@ class Frame(BinaryOperand, Scannable):
         A Frame representing the (optional) index columns.
     """
 
-    _data: "ColumnAccessor"
-
     _VALID_BINARY_OPERATIONS = BinaryOperand._SUPPORTED_BINARY_OPERATIONS
 
-    def __init__(self, data=None):
-        if data is None:
-            data = {}
-        self._data = cudf.core.column_accessor.ColumnAccessor(data)
+    def __init__(self, data: ColumnAccessor | MutableMapping[Any, ColumnBase]):
+        self._data = ColumnAccessor(data)
 
     @property
     def _num_columns(self) -> int:

python/cudf/cudf/core/indexed_frame.py

@@ -265,7 +265,6 @@ class IndexedFrame(Frame):
     # mypy can't handle bound type variables as class members
     _loc_indexer_type: type[_LocIndexerClass]  # type: ignore
     _iloc_indexer_type: type[_IlocIndexerClass]  # type: ignore
-    _index: cudf.core.index.BaseIndex
     _groupby = GroupBy
     _resampler = _Resampler
 
@@ -284,18 +283,21 @@ class IndexedFrame(Frame):
         "cummax": {"op_name": "cumulative max"},
     }
 
-    def __init__(self, data=None, index=None):
+    def __init__(
+        self,
+        data: ColumnAccessor | MutableMapping[Any, ColumnBase],
+        index: BaseIndex,
+    ):
         super().__init__(data=data)
-        # TODO: Right now it is possible to initialize an IndexedFrame without
-        # an index. The code's correctness relies on the subclass constructors
-        # assigning the attribute after the fact. We should restructure those
-        # to ensure that this constructor is always invoked with an index.
+        if not isinstance(index, cudf.core._base_index.BaseIndex):
+            raise ValueError(
+                f"index must be a cudf index not {type(index).__name__}"
+            )
         self._index = index
 
     @property
     def _num_rows(self) -> int:
         # Important to use the index because the data may be empty.
-        # TODO: Remove once DataFrame.__init__ is cleaned up
         return len(self.index)
 
     @property

python/cudf/cudf/core/reshape.py

@@ -490,7 +490,7 @@ def concat(
         elif len(objs) == 1:
             obj = objs[0]
             result = cudf.DataFrame._from_data(
-                data=None if join == "inner" else obj._data.copy(deep=True),
+                data={} if join == "inner" else obj._data.copy(deep=True),
                 index=cudf.RangeIndex(len(obj))
                 if ignore_index
                 else obj.index.copy(deep=True),

python/cudf/cudf/core/series.py

@@ -518,7 +518,7 @@ def from_categorical(cls, categorical, codes=None):
 
     @classmethod
     @_performance_tracking
-    def from_arrow(cls, array: pa.Array):
+    def from_arrow(cls, array: pa.Array) -> Self:
         """Create from PyArrow Array/ChunkedArray.
 
         Parameters