Fix Series/Dataframe Mixed Arithmetic (#7491)

Fixes #7385

Authors:
  - @brandon-b-miller

Approvers:
  - GALI PREM SAGAR (@galipremsagar)
  - Michael Wang (@isVoid)

URL: #7491

python/cudf/cudf/core/dataframe.py

@@ -1518,11 +1518,7 @@ def fallback(col, fn):
                 else:
                     if col not in df_cols:
                         r_opr = other_cols[col]
-                        l_opr = Series(
-                            column_empty(
-                                len(self), masked=True, dtype=other.dtype
-                            )
-                        )
+                        l_opr = Series(as_column(np.nan, length=len(self)))
                     if col not in other_cols_keys:
                         r_opr = None
                         l_opr = self[col]
@@ -2198,7 +2194,7 @@ def rpow(self, other, axis="columns", level=None, fill_value=None):
         return self._apply_op("rpow", other, fill_value)
 
     def __rpow__(self, other):
-        return self._apply_op("__pow__", other)
+        return self._apply_op("__rpow__", other)
 
     def floordiv(self, other, axis="columns", level=None, fill_value=None):
         """

python/cudf/cudf/core/series.py

@@ -1501,9 +1501,7 @@ def _binaryop(
         If ``reflect`` is ``True``, swap the order of the operands.
         """
         if isinstance(other, cudf.DataFrame):
-            # TODO: fn is not the same as arg expected by _apply_op
-            # e.g. for fn = 'and', _apply_op equivalent is '__and__'
-            return other._apply_op(self, fn)
+            return NotImplemented
 
         result_name = utils.get_result_name(self, other)
         if isinstance(other, Series):

python/cudf/cudf/tests/test_dataframe.py

@@ -4996,13 +4996,13 @@ def test_cov_nans():
 @pytest.mark.parametrize(
     "gsr",
     [
-        cudf.Series([1, 2, 3]),
-        cudf.Series([1, 2, 3], index=["a", "b", "c"]),
-        cudf.Series([1, 2, 3], index=["a", "b", "d"]),
-        cudf.Series([1, 2], index=["a", "b"]),
-        cudf.Series([1, 2, 3], index=cudf.core.index.RangeIndex(0, 3)),
+        cudf.Series([4, 2, 3]),
+        cudf.Series([4, 2, 3], index=["a", "b", "c"]),
+        cudf.Series([4, 2, 3], index=["a", "b", "d"]),
+        cudf.Series([4, 2], index=["a", "b"]),
+        cudf.Series([4, 2, 3], index=cudf.core.index.RangeIndex(0, 3)),
         pytest.param(
-            cudf.Series([1, 2, 3, 4, 5], index=["a", "b", "d", "0", "12"]),
+            cudf.Series([4, 2, 3, 4, 5], index=["a", "b", "d", "0", "12"]),
             marks=pytest.mark.xfail,
         ),
     ],
@@ -5017,32 +5017,32 @@ def test_cov_nans():
         operator.truediv,
         operator.mod,
         operator.pow,
-        # comparison ops will temporarily XFAIL
-        # see PR  https://github.com/rapidsai/cudf/pull/7491
-        pytest.param(operator.eq, marks=pytest.mark.xfail()),
-        pytest.param(operator.lt, marks=pytest.mark.xfail()),
-        pytest.param(operator.le, marks=pytest.mark.xfail()),
-        pytest.param(operator.gt, marks=pytest.mark.xfail()),
-        pytest.param(operator.ge, marks=pytest.mark.xfail()),
-        pytest.param(operator.ne, marks=pytest.mark.xfail()),
+        operator.eq,
+        operator.lt,
+        operator.le,
+        operator.gt,
+        operator.ge,
+        operator.ne,
     ],
 )
 def test_df_sr_binop(gsr, colnames, op):
-    data = [[0, 2, 5], [3, None, 5], [6, 7, np.nan]]
+    data = [[3.0, 2.0, 5.0], [3.0, None, 5.0], [6.0, 7.0, np.nan]]
     data = dict(zip(colnames, data))
 
+    gsr = gsr.astype("float64")
+
     gdf = cudf.DataFrame(data)
-    pdf = pd.DataFrame.from_dict(data)
+    pdf = gdf.to_pandas(nullable=True)
 
-    psr = gsr.to_pandas()
+    psr = gsr.to_pandas(nullable=True)
 
     expect = op(pdf, psr)
-    got = op(gdf, gsr)
-    assert_eq(expect.astype(float), got.astype(float))
+    got = op(gdf, gsr).to_pandas(nullable=True)
+    assert_eq(expect, got, check_dtype=False)
 
     expect = op(psr, pdf)
-    got = op(psr, pdf)
-    assert_eq(expect.astype(float), got.astype(float))
+    got = op(gsr, gdf).to_pandas(nullable=True)
+    assert_eq(expect, got, check_dtype=False)
 
 
 @pytest.mark.parametrize(