https://github.com/python/cpython/commit/3e3a4d231518f91ff2f3c5a085b3849e32f1d548
commit: 3e3a4d231518f91ff2f3c5a085b3849e32f1d548
branch: main
author: Victorien <[email protected]>
committer: ericvsmith <[email protected]>
date: 2024-10-01T09:51:51-04:00
summary:
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.
files:
A Misc/NEWS.d/next/Library/2024-08-06-07-24-00.gh-issue-118974.qamsCQ.rst
M Doc/library/dataclasses.rst
M Lib/dataclasses.py
M Lib/test/test_dataclasses/__init__.py
diff --git a/Doc/library/dataclasses.rst b/Doc/library/dataclasses.rst
index 51c1a427b63787..e34b2db0210960 100644
--- a/Doc/library/dataclasses.rst
+++ b/Doc/library/dataclasses.rst
@@ -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
diff --git a/Lib/dataclasses.py b/Lib/dataclasses.py
index bdda7cc6c00f5d..7a24f8a9e5ccee 100644
--- a/Lib/dataclasses.py
+++ b/Lib/dataclasses.py
@@ -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 exec_body_callback(ns):
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)
diff --git a/Lib/test/test_dataclasses/__init__.py
b/Lib/test/test_dataclasses/__init__.py
index 2984f4261bd2c4..2e6c49e29ce828 100644
--- a/Lib/test/test_dataclasses/__init__.py
+++ b/Lib/test/test_dataclasses/__init__.py
@@ -4317,6 +4317,23 @@ def test_funny_class_names_names(self):
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)
diff --git
a/Misc/NEWS.d/next/Library/2024-08-06-07-24-00.gh-issue-118974.qamsCQ.rst
b/Misc/NEWS.d/next/Library/2024-08-06-07-24-00.gh-issue-118974.qamsCQ.rst
new file mode 100644
index 00000000000000..79480a69c1a90e
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-08-06-07-24-00.gh-issue-118974.qamsCQ.rst
@@ -0,0 +1,2 @@
+Add ``decorator`` parameter to :func:`dataclasses.make_dataclass`
+to customize the functional creation of dataclasses.
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