Disallow numeric scalar conversation for non-0D arrays

dpctl/tensor/_usmarray.pyx

@@ -124,6 +124,14 @@ cdef object _as_zero_dim_ndarray(object usm_ary):
     return view
 
 
+cdef inline void _check_0d_scalar_conversion(object usm_ary) except *:
+    "Raise TypeError if array cannot be converted to a Python scalar"
+    if (usm_ary.ndim != 0):
+        raise TypeError(
+            "only 0-dimensional arrays can be converted to Python scalars"
+        )
+
+
 cdef int _copy_writable(int lhs_flags, int rhs_flags):
     "Copy the WRITABLE flag to lhs_flags from rhs_flags"
     return (lhs_flags & ~USM_ARRAY_WRITABLE) | (rhs_flags & USM_ARRAY_WRITABLE)
@@ -1147,6 +1155,7 @@ cdef class usm_ndarray:
 
     def __float__(self):
         if self.size == 1:
+            _check_0d_scalar_conversion(self)
             view = _as_zero_dim_ndarray(self)
             return view.__float__()
 
@@ -1156,6 +1165,7 @@ cdef class usm_ndarray:
 
     def __complex__(self):
         if self.size == 1:
+            _check_0d_scalar_conversion(self)
             view = _as_zero_dim_ndarray(self)
             return view.__complex__()
 
@@ -1165,6 +1175,7 @@ cdef class usm_ndarray:
 
     def __int__(self):
         if self.size == 1:
+            _check_0d_scalar_conversion(self)
             view = _as_zero_dim_ndarray(self)
             return view.__int__()
 

dpctl/tests/test_usm_ndarray_ctor.py

@@ -20,6 +20,7 @@
 
 import numpy as np
 import pytest
+from numpy.testing import assert_raises_regex
 
 import dpctl
 import dpctl.memory as dpm
@@ -282,34 +283,60 @@ def test_properties(dt):
         V.mT
 
 
-@pytest.mark.parametrize("func", [bool, float, int, complex])
 @pytest.mark.parametrize("shape", [tuple(), (1,), (1, 1), (1, 1, 1)])
 @pytest.mark.parametrize("dtype", ["|b1", "|u2", "|f4", "|i8"])
-def test_copy_scalar_with_func(func, shape, dtype):
-    try:
-        X = dpt.usm_ndarray(shape, dtype=dtype)
-    except dpctl.SyclDeviceCreationError:
-        pytest.skip("No SYCL devices available")
-    Y = np.arange(1, X.size + 1, dtype=dtype)
-    X.usm_data.copy_from_host(Y.view("|u1"))
-    Y.shape = tuple()
-    assert func(X) == func(Y)
+class TestCopyScalar:
+    def test_copy_bool_scalar_with_func(self, shape, dtype):
+        try:
+            X = dpt.usm_ndarray(shape, dtype=dtype)
+        except dpctl.SyclDeviceCreationError:
+            pytest.skip("No SYCL devices available")
+        Y = np.arange(1, X.size + 1, dtype=dtype)
+        X.usm_data.copy_from_host(Y.view("|u1"))
+        Y.shape = tuple()
+        assert bool(X) == bool(Y)
 
+    @pytest.mark.parametrize("func", [float, int, complex])
+    def test_copy_numeric_scalar_with_func(self, func, shape, dtype):
+        try:
+            X = dpt.usm_ndarray(shape, dtype=dtype)
+        except dpctl.SyclDeviceCreationError:
+            pytest.skip("No SYCL devices available")
+        Y = np.arange(1, X.size + 1, dtype=dtype)
+        X.usm_data.copy_from_host(Y.view("|u1"))
+        Y.shape = tuple()
+        # Non-0D numeric arrays must not be convertible to Python scalars
+        if len(shape) != 0:
+            assert_raises_regex(TypeError, "only 0-dimensional arrays", func, X)
+        else:
+            # 0D arrays are allowed to convert
+            assert func(X) == func(Y)
+
+    def test_copy_bool_scalar_with_method(self, shape, dtype):
+        try:
+            X = dpt.usm_ndarray(shape, dtype=dtype)
+        except dpctl.SyclDeviceCreationError:
+            pytest.skip("No SYCL devices available")
+        Y = np.arange(1, X.size + 1, dtype=dtype)
+        X.usm_data.copy_from_host(Y.view("|u1"))
+        Y.shape = tuple()
+        assert getattr(X, "__bool__")() == getattr(Y, "__bool__")()
 
-@pytest.mark.parametrize(
-    "method", ["__bool__", "__float__", "__int__", "__complex__"]
-)
-@pytest.mark.parametrize("shape", [tuple(), (1,), (1, 1), (1, 1, 1)])
-@pytest.mark.parametrize("dtype", ["|b1", "|u2", "|f4", "|i8"])
-def test_copy_scalar_with_method(method, shape, dtype):
-    try:
-        X = dpt.usm_ndarray(shape, dtype=dtype)
-    except dpctl.SyclDeviceCreationError:
-        pytest.skip("No SYCL devices available")
-    Y = np.arange(1, X.size + 1, dtype=dtype)
-    X.usm_data.copy_from_host(Y.view("|u1"))
-    Y.shape = tuple()
-    assert getattr(X, method)() == getattr(Y, method)()
+    @pytest.mark.parametrize("method", ["__float__", "__int__", "__complex__"])
+    def test_copy_numeric_scalar_with_method(self, method, shape, dtype):
+        try:
+            X = dpt.usm_ndarray(shape, dtype=dtype)
+        except dpctl.SyclDeviceCreationError:
+            pytest.skip("No SYCL devices available")
+        Y = np.arange(1, X.size + 1, dtype=dtype)
+        X.usm_data.copy_from_host(Y.view("|u1"))
+        Y.shape = tuple()
+        if len(shape) != 0:
+            assert_raises_regex(
+                TypeError, "only 0-dimensional arrays", getattr(X, method)
+            )
+        else:
+            assert getattr(X, method)() == getattr(Y, method)()
 
 
 @pytest.mark.parametrize("func", [bool, float, int, complex])