Remove types.Union serialezation

Lib/test/test_typing.py

@@ -3001,17 +3001,6 @@ def barfoo3(x: BA2): ...
             BA2
         )
 
-        BA3 = typing.Annotated[int | float, "const"]
-        def barfoo4(x: BA3): ...
-        self.assertEqual(
-            get_type_hints(barfoo4, globals(), locals()),
-            {"x": int | float}
-        )
-        self.assertEqual(
-            get_type_hints(barfoo4, globals(), locals(), include_extras=True),
-            {"x": typing.Annotated[int | float, "const"]}
-        )
-
     def test_get_type_hints_annotated_refs(self):
 
         Const = Annotated[T, "Const"]

Lib/typing.py

@@ -322,7 +322,7 @@ def _eval_type(t, globalns, localns, recursive_guard=frozenset()):
         if isinstance(t, GenericAlias):
             return GenericAlias(t.__origin__, ev_args)
         if isinstance(t, types.Union):
-            return types.Union(ev_args)
+            return functools.reduce(operator.or_, ev_args)
         else:
             return t.copy_with(ev_args)
     return t

Misc/NEWS.d/next/Core and Builtins/2021-07-06-22-22-15.bpo-44490.BJxPbZ.rst

@@ -1,3 +1,2 @@
-Add ability to serialize ``types.Union``. Fix ``typing`` module issues with
-``types.Union`` parameters and arguments resolving. Patch provided by Yurii
-Karabas.
+Fix ``typing`` module issues with ``types.Union`` parameters and arguments
+resolving. Patch provided by Yurii Karabas.

Objects/unionobject.c

@@ -428,13 +428,6 @@ union_repr(PyObject *self)
     return NULL;
 }
 
-static PyObject *
-union_reduce(PyObject *self, PyObject *Py_UNUSED(ignored))
-{
-    unionobject *alias = (unionobject *)self;
-    return Py_BuildValue("O(O)", Py_TYPE(alias), alias->args);
-}
-
 static PyMemberDef union_members[] = {
         {"__args__", T_OBJECT, offsetof(unionobject, args), READONLY},
         {0}
@@ -443,7 +436,6 @@ static PyMemberDef union_members[] = {
 static PyMethodDef union_methods[] = {
         {"__instancecheck__", union_instancecheck, METH_O},
         {"__subclasscheck__", union_subclasscheck, METH_O},
-        {"__reduce__", union_reduce, METH_NOARGS},
         {0}};
 
 
@@ -497,42 +489,6 @@ static PyNumberMethods union_as_number = {
         .nb_or = _Py_union_type_or, // Add __or__ function
 };
 
-static PyObject *
-union_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
-{
-    if (!_PyArg_NoKeywords("Union", kwds)) {
-        return NULL;
-    }
-    if (!_PyArg_CheckPositional("Union", PyTuple_GET_SIZE(args), 1, 1)) {
-        return NULL;
-    }
-
-    return _Py_Union(PyTuple_GET_ITEM(args, 0));
-}
-
-static const char* const cls_attrs[] = {
-        "__name__",
-        "__qualname__",
-        "__module__",
-        NULL,
-};
-
-static PyObject *
-union_getattro(PyObject *self, PyObject *name)
-{
-    unionobject *alias = (unionobject  *)self;
-
-    for (const char * const *p = cls_attrs; ; p++) {
-        if (*p == NULL) {
-            break;
-        }
-        if (_PyUnicode_EqualToASCIIString(name, *p)) {
-            return PyObject_GetAttr((PyObject *) Py_TYPE(alias), name);
-        }
-    }
-    return PyObject_GenericGetAttr(self, name);
-}
-
 PyTypeObject _Py_UnionType = {
     PyVarObject_HEAD_INIT(&PyType_Type, 0)
     .tp_name = "types.Union",
@@ -546,15 +502,14 @@ PyTypeObject _Py_UnionType = {
     .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,
     .tp_traverse = union_traverse,
     .tp_hash = union_hash,
-    .tp_getattro = union_getattro,
+    .tp_getattro = PyObject_GenericGetAttr,
     .tp_members = union_members,
     .tp_methods = union_methods,
     .tp_richcompare = union_richcompare,
     .tp_as_mapping = &union_as_mapping,
     .tp_as_number = &union_as_number,
     .tp_repr = union_repr,
     .tp_getset = union_properties,
-    .tp_new = union_new,
 };
 
 PyObject *