Add FixedShapeTensorScalarType

python/pyarrow/array.pxi

@@ -3325,6 +3325,23 @@ cdef class ExtensionArray(Array):
         return result
 
 
+class FixedShapeTensorScalarType(ExtensionScalar):
+    """
+    Concrete class for fixed shape tensor extension scalar type.
+    """
+    def to_numpy_ndarray(self):
+        """
+        Convert fixed shape tensor extension scalar to a numpy array (with dim+1).
+        """
+        self.to_numpy_ndarray()
+
+    def as_py(self):
+        """
+        Convert fixed shape tensor extension scalar to a python list.
+        """
+        return self.to_numpy_ndarray().tolist()
+
+
 class FixedShapeTensorArray(ExtensionArray):
     """
     Concrete class for fixed shape tensor extension arrays.
@@ -3433,6 +3450,9 @@ class FixedShapeTensorArray(ExtensionArray):
             FixedSizeListArray.from_arrays(np.ravel(obj, order='C'), size)
         )
 
+    def __arrow_ext_scalar_class__(self):
+        return FixedShapeTensorScalarType
+
 
 cdef dict _array_classes = {
     _Type_NA: NullArray,

python/pyarrow/tests/test_extension_type.py

@@ -1247,6 +1247,9 @@ def test_tensor_class_methods():
     with pytest.raises(ValueError, match="non-permuted tensors"):
         arr.to_numpy_ndarray()
 
+    for i in range(expected.shape[0]):
+        assert arr[i].to_numpy_ndarray() == expected[i]
+
 
 @pytest.mark.parametrize("tensor_type", (
     pa.fixed_shape_tensor(pa.int8(), [2, 2, 3]),