Merge pull request #20527 from asmeurer/array_api-__array__

ENH: Add __array__ to the array_api Array object

Original NumPy Commit: b5331ea9ece515d45e5a5adcb8e06117c9d33569

Author: charris

array_api_strict/_array_object.py

@@ -33,6 +33,7 @@
 
 if TYPE_CHECKING:
     from ._typing import Any, PyCapsule, Device, Dtype
+    import numpy.typing as npt
 
 import numpy as np
 
@@ -108,6 +109,17 @@ def __repr__(self: Array, /) -> str:
             mid = np.array2string(self._array, separator=', ', prefix=prefix, suffix=suffix)
         return prefix + mid + suffix
 
+    # This function is not required by the spec, but we implement it here for
+    # convenience so that np.asarray(np.array_api.Array) will work.
+    def __array__(self, dtype: None | np.dtype[Any] = None) -> npt.NDArray[Any]:
+        """
+        Warning: this method is NOT part of the array API spec. Implementers
+        of other libraries need not include it, and users should not assume it
+        will be present in other implementations.
+
+        """
+        return np.asarray(self._array, dtype=dtype)
+
     # These are various helper functions to make the array behavior match the
     # spec in places where it either deviates from or is more strict than
     # NumPy behavior

array_api_strict/tests/test_array_object.py

@@ -315,3 +315,10 @@ def test_array_properties():
     assert a.mT.shape == (1, 3, 2)
     assert isinstance(b.mT, Array)
     assert b.mT.shape == (3, 2)
+
+def test___array__():
+    a = ones((2, 3), dtype=int16)
+    assert np.asarray(a) is a._array
+    b = np.asarray(a, dtype=np.float64)
+    assert np.all(np.equal(b, np.ones((2, 3), dtype=np.float64)))
+    assert b.dtype == np.float64