gh-118974: Add `decorator` argument to `make_dataclass` (gh-122723)

This is to allow the `dataclasses.make_dataclass` infrastructure to be used with another decorator that's compliant with `typing.dataclass_transform`. The new `decorator` argument to `dataclasses.make_dataclass` is `dataclasses.dataclass`, which used to be hard coded.
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Victorien 2024-10-01 15:51:51 +02:00 committed by GitHub
parent 91e64be731
commit 3e3a4d2315
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4 changed files with 31 additions and 4 deletions

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@ -399,7 +399,7 @@ Module contents
:func:`!astuple` raises :exc:`TypeError` if *obj* is not a dataclass
instance.
.. function:: make_dataclass(cls_name, fields, *, bases=(), namespace=None, init=True, repr=True, eq=True, order=False, unsafe_hash=False, frozen=False, match_args=True, kw_only=False, slots=False, weakref_slot=False, module=None)
.. function:: make_dataclass(cls_name, fields, *, bases=(), namespace=None, init=True, repr=True, eq=True, order=False, unsafe_hash=False, frozen=False, match_args=True, kw_only=False, slots=False, weakref_slot=False, module=None, decorator=dataclass)
Creates a new dataclass with name *cls_name*, fields as defined
in *fields*, base classes as given in *bases*, and initialized
@ -415,6 +415,11 @@ Module contents
of the dataclass is set to that value.
By default, it is set to the module name of the caller.
The *decorator* parameter is a callable that will be used to create the dataclass.
It should take the class object as a first argument and the same keyword arguments
as :func:`@dataclass <dataclass>`. By default, the :func:`@dataclass <dataclass>`
function is used.
This function is not strictly required, because any Python
mechanism for creating a new class with :attr:`!__annotations__` can
then apply the :func:`@dataclass <dataclass>` function to convert that class to
@ -438,6 +443,9 @@ Module contents
def add_one(self):
return self.x + 1
.. versionadded:: 3.14
Added the *decorator* parameter.
.. function:: replace(obj, /, **changes)
Creates a new object of the same type as *obj*, replacing

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@ -1550,7 +1550,7 @@ def _astuple_inner(obj, tuple_factory):
def make_dataclass(cls_name, fields, *, bases=(), namespace=None, init=True,
repr=True, eq=True, order=False, unsafe_hash=False,
frozen=False, match_args=True, kw_only=False, slots=False,
weakref_slot=False, module=None):
weakref_slot=False, module=None, decorator=dataclass):
"""Return a new dynamically created dataclass.
The dataclass name will be 'cls_name'. 'fields' is an iterable
@ -1630,8 +1630,8 @@ def make_dataclass(cls_name, fields, *, bases=(), namespace=None, init=True,
if module is not None:
cls.__module__ = module
# Apply the normal decorator.
return dataclass(cls, init=init, repr=repr, eq=eq, order=order,
# Apply the normal provided decorator.
return decorator(cls, init=init, repr=repr, eq=eq, order=order,
unsafe_hash=unsafe_hash, frozen=frozen,
match_args=match_args, kw_only=kw_only, slots=slots,
weakref_slot=weakref_slot)

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@ -4317,6 +4317,23 @@ class TestMakeDataclass(unittest.TestCase):
C = make_dataclass(classname, ['a', 'b'])
self.assertEqual(C.__name__, classname)
def test_dataclass_decorator_default(self):
C = make_dataclass('C', [('x', int)], decorator=dataclass)
c = C(10)
self.assertEqual(c.x, 10)
def test_dataclass_custom_decorator(self):
def custom_dataclass(cls, *args, **kwargs):
dc = dataclass(cls, *args, **kwargs)
dc.__custom__ = True
return dc
C = make_dataclass('C', [('x', int)], decorator=custom_dataclass)
c = C(10)
self.assertEqual(c.x, 10)
self.assertEqual(c.__custom__, True)
class TestReplace(unittest.TestCase):
def test(self):
@dataclass(frozen=True)

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@ -0,0 +1,2 @@
Add ``decorator`` parameter to :func:`dataclasses.make_dataclass`
to customize the functional creation of dataclasses.