Sep 16, 2023 · Sep 16, 2023 · Sep 16, 2023 · Sep 16, 2023 · Sep 25, 2023 · Oct 2, 2023
diff --git a/Lib/copy.py b/Lib/copy.py
    pass
 error = Error   # backward compatibility

 _NoValue = object()

 __all__ = ["Error", "copy", "deepcopy", "replace"]

 def copy(x):
        # treat it as a regular class:
        return x

    copier = getattr(cls, "__copy__",None)
    if copier is notNone:
    copier = getattr(cls, "__copy__",_NoValue)
    if copier is not_NoValue:
        return copier(x)

    reductor = dispatch_table.get(cls)
    if reductor is notNone:
    reductor = dispatch_table.get(cls, _NoValue)
    if reductor is not_NoValue:
        rv = reductor(x)
    else:
        reductor = getattr(x, "__reduce_ex__",None)
        if reductor is notNone:
        reductor = getattr(x, "__reduce_ex__",_NoValue)
        if reductor is not_NoValue:
            rv = reductor(4)
        else:
            reductor = getattr(x, "__reduce__",None)
            if reductor:
            reductor = getattr(x, "__reduce__",_NoValue)
            if reductor is not _NoValue:
                rv = reductor()
            else:
                raise Error("un(shallow)copyable object of type %s" % cls)
        if issubclass(cls, type):
            y = x # atomic copy
        else:
            copier = getattr(x, "__deepcopy__",None)
            if copier is notNone:
            copier = getattr(x, "__deepcopy__",_NoValue)
            if copier is not_NoValue:
                y = copier(memo)
            else:
                reductor = dispatch_table.get(cls)
                if reductor:
                    rv = reductor(x)
                else:
                    reductor = getattr(x, "__reduce_ex__",None)
                    if reductor is notNone:
                    reductor = getattr(x, "__reduce_ex__",_NoValue)
                    if reductor is not_NoValue:
                        rv = reductor(4)
                    else:
                        reductor = getattr(x, "__reduce__",None)
                        if reductor:
                        reductor = getattr(x, "__reduce__",_NoValue)
                        if reductor is not _NoValue:
                            rv = reductor()
                        else:
                            raise Error(
    frozen dataclasses.
    """
    cls = obj.__class__
    func = getattr(cls, '__replace__',None)
    if func isNone:
    func = getattr(cls, '__replace__',_NoValue)
    if func is_NoValue:
        raise TypeError(f"replace() does not support {cls.__name__} objects")
    return func(obj, **changes)
diff --git a/Lib/test/test_copy.py b/Lib/test/test_copy.py
        self.assertIs(y, x)
        self.assertEqual(c, [1])

    def test_copy_invalid_reduction_methods(self):
        class C(object):
            __copy__ = None
        x = C()
        with self.assertRaises(TypeError):
            copy.copy(x)

        class C(object):
            __reduce_ex__ = None
        x = C()
        with self.assertRaises(TypeError):
            copy.copy(x)

        class C(object):
            __reduce_ex__ = copy._NoValue
            __reduce__ = None
        x = C()
        with self.assertRaises(TypeError):
            copy.copy(x)

    def test_copy_reduce(self):
        class C(object):
            def __reduce__(self):
        with self.assertRaisesRegex(TypeError, 'unexpected keyword argument'):
            copy.replace(c, x=1, error=2)

    def test_invalid_replace_method(self):
        class A:
            __replace__ = None
        a = A()
        with self.assertRaises(TypeError):
            copy.replace(a)


 class MiscTestCase(unittest.TestCase):
    def test__all__(self):
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2023-09-16-19-19-47.gh-issue-93627.fkb529.rst b/Misc/NEWS.d/next/Core_and_Builtins/2023-09-16-19-19-47.gh-issue-93627.fkb529.rst
 Update the Python copy module implementation to match the implementation of the pickle module. For objects setting reduction methods like :meth:`~object.__copy__` , :meth:`~object.__reduce_ex__` or :meth:`~object.__reduce__` to ``None``, a call to :meth:`copy.copy` or :meth:`copy.deepcopy` will result in a :exc:`TypeError`.
Original file line number	Diff line number	Diff line change
Expand Up		@@ -57,6 +57,8 @@ class Error(Exception):
		pass
		error = Error # backward compatibility

		_NoValue = object()

		__all__ = ["Error", "copy", "deepcopy", "replace"]

		def copy(x):
Expand All		@@ -77,20 +79,20 @@ def copy(x):
		# treat it as a regular class:
		return x

		copier = getattr(cls, "__copy__",None)
		if copier is notNone:
		copier = getattr(cls, "__copy__",_NoValue)
		if copier is not_NoValue:
		return copier(x)

		reductor = dispatch_table.get(cls)
		if reductor is notNone:
		reductor = dispatch_table.get(cls, _NoValue)
		if reductor is not_NoValue:
		rv = reductor(x)
		else:
		reductor = getattr(x, "__reduce_ex__",None)
		if reductor is notNone:
		reductor = getattr(x, "__reduce_ex__",_NoValue)
		if reductor is not_NoValue:
		rv = reductor(4)
		else:
		reductor = getattr(x, "__reduce__",None)
		if reductor:
		reductor = getattr(x, "__reduce__",_NoValue)
		if reductor is not _NoValue:
		rv = reductor()
		else:
		raise Error("un(shallow)copyable object of type %s" % cls)
Expand DownExpand Up		@@ -133,20 +135,20 @@ def deepcopy(x, memo=None, _nil=[]):
		if issubclass(cls, type):
		y = x # atomic copy
		else:
		copier = getattr(x, "__deepcopy__",None)
		if copier is notNone:
		copier = getattr(x, "__deepcopy__",_NoValue)
		if copier is not_NoValue:
		y = copier(memo)
		else:
		reductor = dispatch_table.get(cls)
		if reductor:
		rv = reductor(x)
		else:
		reductor = getattr(x, "__reduce_ex__",None)
		if reductor is notNone:
		reductor = getattr(x, "__reduce_ex__",_NoValue)
		if reductor is not_NoValue:
		rv = reductor(4)
		else:
		reductor = getattr(x, "__reduce__",None)
		if reductor:
		reductor = getattr(x, "__reduce__",_NoValue)
		if reductor is not _NoValue:
		rv = reductor()
		else:
		raise Error(
Expand DownExpand Up		@@ -280,7 +282,7 @@ def replace(obj, /, **changes):
		frozen dataclasses.
		"""
		cls = obj.__class__
		func = getattr(cls, '__replace__',None)
		if func isNone:
		func = getattr(cls, '__replace__',_NoValue)
		if func is_NoValue:
		raise TypeError(f"replace() does not support {cls.__name__} objects")
		return func(obj, **changes)
Original file line number	Diff line number	Diff line change
Expand Up		@@ -68,6 +68,26 @@ def __reduce__(self):
		self.assertIs(y, x)
		self.assertEqual(c, [1])

		def test_copy_invalid_reduction_methods(self):
		class C(object):
		__copy__ = None
		x = C()
		with self.assertRaises(TypeError):
		copy.copy(x)

		class C(object):
		__reduce_ex__ = None
		x = C()
		with self.assertRaises(TypeError):
		copy.copy(x)

		class C(object):
		__reduce_ex__ = copy._NoValue
		__reduce__ = None
		x = C()
		with self.assertRaises(TypeError):
		copy.copy(x)

		def test_copy_reduce(self):
		class C(object):
		def __reduce__(self):
Expand DownExpand Up		@@ -977,6 +997,13 @@ class C:
		with self.assertRaisesRegex(TypeError, 'unexpected keyword argument'):
		copy.replace(c, x=1, error=2)

		def test_invalid_replace_method(self):
		class A:
		__replace__ = None
		a = A()
		with self.assertRaises(TypeError):
		copy.replace(a)


		class MiscTestCase(unittest.TestCase):
		def test__all__(self):
Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Update the Python copy module implementation to match the implementation of the pickle module. For objects setting reduction methods like :meth:`~object.__copy__` , :meth:`~object.__reduce_ex__` or :meth:`~object.__reduce__` to ``None``, a call to :meth:`copy.copy` or :meth:`copy.deepcopy` will result in a :exc:`TypeError`.