BUG: Invalid dtypes comparison should not raise TypeError

numpy/__init__.pyi

@@ -1075,8 +1075,6 @@ class dtype(Generic[_DTypeScalar_co]):
     # literals as of mypy 0.800. Set the return-type to `Any` for now.
     def __rmul__(self, value: int) -> Any: ...
 
-    def __eq__(self, other: DTypeLike) -> bool: ...
-    def __ne__(self, other: DTypeLike) -> bool: ...
     def __gt__(self, other: DTypeLike) -> bool: ...
     def __ge__(self, other: DTypeLike) -> bool: ...
     def __lt__(self, other: DTypeLike) -> bool: ...

numpy/core/src/multiarray/descriptor.c

@@ -3228,7 +3228,9 @@ arraydescr_richcompare(PyArray_Descr *self, PyObject *other, int cmp_op)
 {
     PyArray_Descr *new = _convert_from_any(other, 0);
     if (new == NULL) {
-        return NULL;
+        /* Cannot convert `other` to dtype */
+        PyErr_Clear();
+        Py_RETURN_NOTIMPLEMENTED;
     }
 
     npy_bool ret;

numpy/core/tests/test_dtype.py

@@ -88,6 +88,24 @@ def test_invalid_types(self):
             assert_raises(TypeError, np.dtype, 'q8')
             assert_raises(TypeError, np.dtype, 'Q8')
 
+    def test_richcompare_invalid_dtype_equality(self):
+        # Make sure objects that cannot be converted to valid
+        # dtypes results in False/True when compared to valid dtypes.
+        # Here 7 cannot be converted to dtype. No exceptions should be raised
+
+        assert not np.dtype(np.int32) == 7, "dtype richcompare failed for =="
+        assert np.dtype(np.int32) != 7, "dtype richcompare failed for !="
+
+    @pytest.mark.parametrize(
+        'operation',
+        [operator.le, operator.lt, operator.ge, operator.gt])
+    def test_richcompare_invalid_dtype_comparison(self, operation):
+        # Make sure TypeError is raised for comparison operators
+        # for invalid dtypes. Here 7 is an invalid dtype.
+
+        with pytest.raises(TypeError):
+            operation(np.dtype(np.int32), 7)
+
     @pytest.mark.parametrize("dtype",
              ['Bool', 'Complex32', 'Complex64', 'Float16', 'Float32', 'Float64',
               'Int8', 'Int16', 'Int32', 'Int64', 'Object0', 'Timedelta64',