Merge pull request #4770 from galipremsagar/4623

[REVIEW] Fix readonly flag in `Column. __cuda_array_interface__`

CHANGELOG.md

@@ -81,6 +81,7 @@
 - PR #4755 Fix Java build to deal with new quantiles API 
 - PR #4720 Fix issue related to `dtype` param not being adhered incase of cuda arrays
 - PR #4777 Fix data pointer for column slices of zero length
+- PR #4770 Fix readonly flag in `Column. __cuda_array_interface__`
 
 
 # cuDF 0.13.0 (31 Mar 2020)

python/cudf/cudf/core/column/column.py

@@ -828,7 +828,7 @@ def __cuda_array_interface__(self):
             "shape": (len(self),),
             "strides": (self.dtype.itemsize,),
             "typestr": self.dtype.str,
-            "data": (self.data_ptr, True),
+            "data": (self.data_ptr, False),
             "version": 1,
         }
 

python/cudf/cudf/tests/test_cuda_array_interface.py

@@ -186,3 +186,49 @@ def test_column_from_ephemeral_cupy_try_lose_reference():
     a.name = "b"
     b = cupy.asarray([1, 1, 1])  # noqa: F841
     assert_eq(pd.Series([1, 2, 3]), a.to_pandas())
+
+
+@pytest.mark.skipif(
+    cupy.cuda.runtime.runtimeGetVersion() >= 10020,
+    reason="Pytorch doesn't support 10.2 cuda yet \
+        without building from source.",
+)
+def test_cuda_array_interface_pytorch():
+    torch = pytest.importorskip("torch")
+    series = cudf.Series([1, -1, 10, -56])
+    tensor = torch.tensor(series)
+    got = cudf.Series(tensor)
+
+    assert_eq(got, series)
+    from cudf.core.buffer import Buffer
+
+    buffer = Buffer(cupy.ones(10, dtype=np.bool_))
+    tensor = torch.tensor(buffer)
+    got = cudf.Series(tensor, dtype=np.bool_)
+
+    assert_eq(got, cudf.Series(buffer, dtype=np.bool_))
+
+    with pytest.raises(RuntimeError):
+        torch.tensor(cudf.core.Index())
+
+    index = cudf.core.index.RangeIndex(start=0, stop=100)
+    tensor = torch.tensor(index)
+    got = cudf.Series(tensor)
+
+    assert_eq(got, cudf.Series(index))
+
+    index = cudf.core.index.GenericIndex([1, 2, 8, 6])
+    tensor = torch.tensor(index)
+    got = cudf.Series(tensor)
+
+    assert_eq(got, cudf.Series(index))
+
+    str_series = cudf.Series(["a", "g"])
+
+    with pytest.raises(NotImplementedError):
+        str_series.__cuda_array_interface__
+
+    cat_series = str_series.astype("category")
+
+    with pytest.raises(TypeError):
+        cat_series.__cuda_array_interface__