[API Compatibility] Fix tensor __eq__ and __ne__ for unsupported type

paddle/fluid/pybind/eager_math_op_patch.cc

@@ -2283,8 +2283,16 @@ static PyObject* tensor__eq__method(TensorObject* self,
       other_tensor = paddle::empty({}, phi::DataType::FLOAT32, place);
       InitTensorWithNumpyValue(numpy_value, place, &other_tensor);
     } else {
-      paddle::experimental::Scalar value =
-          CastPyArg2Scalar(other_obj, "__eq__", 0);
+      paddle::experimental::Scalar value;
+
+      // return False if other_obj is unsupported type
+      try {
+        value = CastPyArg2Scalar(other_obj, "__eq__", 0);
+      } catch (const ::common::enforce::EnforceNotMet& e) {
+        Py_INCREF(Py_False);
+        return Py_False;
+      }
+
       if (PyComplex_Check(other_obj)) {
         eager_gil_scoped_release guard;
         other_tensor =

test/legacy_test/test_eager_tensor.py

@@ -401,7 +401,9 @@ def test_tensor_pin_memory_and_device(self):
 
         with self.assertRaises(RuntimeError) as context:
             paddle.tensor(
-                self.array, device="cpu", pin_memory=True  # no support
+                self.array,
+                device="cpu",
+                pin_memory=True,  # no support
             )
         self.assertIn(
             "Pinning memory is not supported",
@@ -1529,6 +1531,19 @@ def test_tensor__format__(self):
         paddle_scalar = paddle.uniform([], min=-100, max=100)
         self.assertRaises(ValueError, paddle_scalar.__format__, "3d")
 
+    def test_tensor_eq_unsupported_type(self):
+        a = paddle.empty([2])
+
+        # Compare with None
+        self.assertFalse(a == None)  # noqa: E711
+        self.assertTrue(a != None)  # noqa: E711
+
+        # Compare with other obj
+        self.assertFalse(a == "a string")
+        self.assertTrue(a != "a string")
+        self.assertFalse(a == object())
+        self.assertTrue(a != object())
+
 
 class TestEagerTensorSetitem(unittest.TestCase):
     def func_setUp(self):