diff --git a/Doc/library/dataclasses.rst b/Doc/library/dataclasses.rst index 447f05e67d8418..c72ad945681955 100644 --- a/Doc/library/dataclasses.rst +++ b/Doc/library/dataclasses.rst @@ -371,8 +371,8 @@ Module contents Converts the dataclass *obj* to a dict (by using the factory function *dict_factory*). Each dataclass is converted to a dict of its fields, as ``name: value`` pairs. dataclasses, dicts, - lists, and tuples are recursed into. Other objects are copied with - :func:`copy.deepcopy`. + frozendicts, lists, and tuples are recursed into. Other objects are copied + with :func:`copy.deepcopy`. Example of using :func:`!asdict` on nested dataclasses:: @@ -402,8 +402,8 @@ Module contents Converts the dataclass *obj* to a tuple (by using the factory function *tuple_factory*). Each dataclass is converted - to a tuple of its field values. dataclasses, dicts, lists, and - tuples are recursed into. Other objects are copied with + to a tuple of its field values. dataclasses, dicts, frozendicts, lists, + and tuples are recursed into. Other objects are copied with :func:`copy.deepcopy`. Continuing from the previous example:: diff --git a/Lib/dataclasses.py b/Lib/dataclasses.py index 482a4c61039184..00b270fa6b5460 100644 --- a/Lib/dataclasses.py +++ b/Lib/dataclasses.py @@ -1490,7 +1490,8 @@ class C: If given, 'dict_factory' will be used instead of built-in dict. The function applies recursively to field values that are dataclass instances. This will also look into built-in containers: - tuples, lists, and dicts. Other objects are copied with 'copy.deepcopy()'. + tuples, lists, dicts, and frozendicts. Other objects are copied + with 'copy.deepcopy()'. """ if not _is_dataclass_instance(obj): raise TypeError("asdict() should be called on dataclass instances") @@ -1546,7 +1547,7 @@ def _asdict_inner(obj, dict_factory): return obj_type(*[_asdict_inner(v, dict_factory) for v in obj]) else: return obj_type(_asdict_inner(v, dict_factory) for v in obj) - elif issubclass(obj_type, dict): + elif issubclass(obj_type, (dict, frozendict)): if hasattr(obj_type, 'default_factory'): # obj is a defaultdict, which has a different constructor from # dict as it requires the default_factory as its first arg. @@ -1581,7 +1582,8 @@ class C: If given, 'tuple_factory' will be used instead of built-in tuple. The function applies recursively to field values that are dataclass instances. This will also look into built-in containers: - tuples, lists, and dicts. Other objects are copied with 'copy.deepcopy()'. + tuples, lists, dicts, and frozendicts. Other objects are copied + with 'copy.deepcopy()'. """ if not _is_dataclass_instance(obj): @@ -1610,7 +1612,7 @@ def _astuple_inner(obj, tuple_factory): # generator (which is not true for namedtuples, handled # above). return type(obj)(_astuple_inner(v, tuple_factory) for v in obj) - elif isinstance(obj, dict): + elif isinstance(obj, (dict, frozendict)): obj_type = type(obj) if hasattr(obj_type, 'default_factory'): # obj is a defaultdict, which has a different constructor from diff --git a/Lib/test/test_dataclasses/__init__.py b/Lib/test/test_dataclasses/__init__.py index 8b5e0cf7806ba9..37ecb5e02873da 100644 --- a/Lib/test/test_dataclasses/__init__.py +++ b/Lib/test/test_dataclasses/__init__.py @@ -1693,17 +1693,24 @@ class GroupTuple: class GroupDict: id: int users: Dict[str, User] + @dataclass + class GroupFrozenDict: + id: int + users: frozendict[str, User] a = User('Alice', 1) b = User('Bob', 2) gl = GroupList(0, [a, b]) gt = GroupTuple(0, (a, b)) gd = GroupDict(0, {'first': a, 'second': b}) + gfd = GroupFrozenDict(0, frozendict({'first': a, 'second': b})) self.assertEqual(asdict(gl), {'id': 0, 'users': [{'name': 'Alice', 'id': 1}, {'name': 'Bob', 'id': 2}]}) self.assertEqual(asdict(gt), {'id': 0, 'users': ({'name': 'Alice', 'id': 1}, {'name': 'Bob', 'id': 2})}) - self.assertEqual(asdict(gd), {'id': 0, 'users': {'first': {'name': 'Alice', 'id': 1}, - 'second': {'name': 'Bob', 'id': 2}}}) + expected_dict = {'id': 0, 'users': {'first': {'name': 'Alice', 'id': 1}, + 'second': {'name': 'Bob', 'id': 2}}} + self.assertEqual(asdict(gd), expected_dict) + self.assertEqual(asdict(gfd), expected_dict) def test_helper_asdict_builtin_object_containers(self): @dataclass @@ -1884,14 +1891,21 @@ class GroupTuple: class GroupDict: id: int users: Dict[str, User] + @dataclass + class GroupFrozenDict: + id: int + users: frozendict[str, User] a = User('Alice', 1) b = User('Bob', 2) gl = GroupList(0, [a, b]) gt = GroupTuple(0, (a, b)) gd = GroupDict(0, {'first': a, 'second': b}) + gfd = GroupFrozenDict(0, frozendict({'first': a, 'second': b})) self.assertEqual(astuple(gl), (0, [('Alice', 1), ('Bob', 2)])) self.assertEqual(astuple(gt), (0, (('Alice', 1), ('Bob', 2)))) - self.assertEqual(astuple(gd), (0, {'first': ('Alice', 1), 'second': ('Bob', 2)})) + d = {'first': ('Alice', 1), 'second': ('Bob', 2)} + self.assertEqual(astuple(gd), (0, d)) + self.assertEqual(astuple(gfd), (0, frozendict(d))) def test_helper_astuple_builtin_object_containers(self): @dataclass diff --git a/Misc/NEWS.d/next/Library/2026-02-22-19-36-00.gh-issue-145056.TH8nX4.rst b/Misc/NEWS.d/next/Library/2026-02-22-19-36-00.gh-issue-145056.TH8nX4.rst new file mode 100644 index 00000000000000..45be0109677cd1 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2026-02-22-19-36-00.gh-issue-145056.TH8nX4.rst @@ -0,0 +1 @@ +Add support for :class:`frozendict` in :meth:`dataclasses.asdict` and :meth:`dataclasses.astuple`.