diff --git a/Lib/annotationlib.py b/Lib/annotationlib.py index 5ad0893106a72b..c0b1d4395d14ed 100644 --- a/Lib/annotationlib.py +++ b/Lib/annotationlib.py @@ -868,7 +868,7 @@ def get_annotations( # For FORWARDREF, we use __annotations__ if it exists try: ann = _get_dunder_annotations(obj) - except NameError: + except Exception: pass else: if ann is not None: diff --git a/Lib/dataclasses.py b/Lib/dataclasses.py index 0f7dc9ae6b82f5..86d29df0639184 100644 --- a/Lib/dataclasses.py +++ b/Lib/dataclasses.py @@ -244,6 +244,10 @@ def __repr__(self): property, }) +# Any marker is used in `make_dataclass` to mark unannotated fields as `Any` +# without importing `typing` module. +_ANY_MARKER = object() + class InitVar: __slots__ = ('type', ) @@ -1591,7 +1595,7 @@ class C(Base): for item in fields: if isinstance(item, str): name = item - tp = 'typing.Any' + tp = _ANY_MARKER elif len(item) == 2: name, tp, = item elif len(item) == 3: @@ -1610,15 +1614,49 @@ class C(Base): seen.add(name) annotations[name] = tp + # We initially block the VALUE format, because inside dataclass() we'll + # call get_annotations(), which will try the VALUE format first. If we don't + # block, that means we'd always end up eagerly importing typing here, which + # is what we're trying to avoid. + value_blocked = True + + def annotate_method(format): + def get_any(): + match format: + case annotationlib.Format.STRING: + return 'typing.Any' + case annotationlib.Format.FORWARDREF: + typing = sys.modules.get("typing") + if typing is None: + return annotationlib.ForwardRef("Any", module="typing") + else: + return typing.Any + case annotationlib.Format.VALUE: + if value_blocked: + raise NotImplementedError + from typing import Any + return Any + case _: + raise NotImplementedError + annos = { + ann: get_any() if t is _ANY_MARKER else t + for ann, t in annotations.items() + } + if format == annotationlib.Format.STRING: + return annotationlib.annotations_to_string(annos) + else: + return annos + # Update 'ns' with the user-supplied namespace plus our calculated values. def exec_body_callback(ns): ns.update(namespace) ns.update(defaults) - ns['__annotations__'] = annotations # We use `types.new_class()` instead of simply `type()` to allow dynamic creation # of generic dataclasses. cls = types.new_class(cls_name, bases, {}, exec_body_callback) + # For now, set annotations including the _ANY_MARKER. + cls.__annotate__ = annotate_method # For pickling to work, the __module__ variable needs to be set to the frame # where the dataclass is created. @@ -1634,10 +1672,13 @@ def exec_body_callback(ns): cls.__module__ = module # 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) + cls = 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) + # Now that the class is ready, allow the VALUE format. + value_blocked = False + return cls def replace(obj, /, **changes): diff --git a/Lib/test/test_dataclasses/__init__.py b/Lib/test/test_dataclasses/__init__.py index 99fefb57fd0f09..ac78f8327b808e 100644 --- a/Lib/test/test_dataclasses/__init__.py +++ b/Lib/test/test_dataclasses/__init__.py @@ -5,6 +5,7 @@ from dataclasses import * import abc +import annotationlib import io import pickle import inspect @@ -12,6 +13,7 @@ import types import weakref import traceback +import sys import textwrap import unittest from unittest.mock import Mock @@ -25,6 +27,7 @@ import dataclasses # Needed for the string "dataclasses.InitVar[int]" to work as an annotation. from test import support +from test.support import import_helper # Just any custom exception we can catch. class CustomError(Exception): pass @@ -3754,7 +3757,6 @@ class A(WithDictSlot): ... @support.cpython_only def test_dataclass_slot_dict_ctype(self): # https://github.com/python/cpython/issues/123935 - from test.support import import_helper # Skips test if `_testcapi` is not present: _testcapi = import_helper.import_module('_testcapi') @@ -4246,16 +4248,56 @@ def test_no_types(self): C = make_dataclass('Point', ['x', 'y', 'z']) c = C(1, 2, 3) self.assertEqual(vars(c), {'x': 1, 'y': 2, 'z': 3}) - self.assertEqual(C.__annotations__, {'x': 'typing.Any', - 'y': 'typing.Any', - 'z': 'typing.Any'}) + self.assertEqual(C.__annotations__, {'x': typing.Any, + 'y': typing.Any, + 'z': typing.Any}) C = make_dataclass('Point', ['x', ('y', int), 'z']) c = C(1, 2, 3) self.assertEqual(vars(c), {'x': 1, 'y': 2, 'z': 3}) - self.assertEqual(C.__annotations__, {'x': 'typing.Any', + self.assertEqual(C.__annotations__, {'x': typing.Any, 'y': int, - 'z': 'typing.Any'}) + 'z': typing.Any}) + + def test_no_types_get_annotations(self): + C = make_dataclass('C', ['x', ('y', int), 'z']) + + self.assertEqual( + annotationlib.get_annotations(C, format=annotationlib.Format.VALUE), + {'x': typing.Any, 'y': int, 'z': typing.Any}, + ) + self.assertEqual( + annotationlib.get_annotations( + C, format=annotationlib.Format.FORWARDREF), + {'x': typing.Any, 'y': int, 'z': typing.Any}, + ) + self.assertEqual( + annotationlib.get_annotations( + C, format=annotationlib.Format.STRING), + {'x': 'typing.Any', 'y': 'int', 'z': 'typing.Any'}, + ) + + def test_no_types_no_typing_import(self): + with import_helper.CleanImport('typing'): + self.assertNotIn('typing', sys.modules) + C = make_dataclass('C', ['x', ('y', int)]) + + self.assertNotIn('typing', sys.modules) + self.assertEqual( + C.__annotate__(annotationlib.Format.FORWARDREF), + { + 'x': annotationlib.ForwardRef('Any', module='typing'), + 'y': int, + }, + ) + self.assertNotIn('typing', sys.modules) + + for field in fields(C): + if field.name == "x": + self.assertEqual(field.type, annotationlib.ForwardRef('Any', module='typing')) + else: + self.assertEqual(field.name, "y") + self.assertIs(field.type, int) def test_module_attr(self): self.assertEqual(ByMakeDataClass.__module__, __name__) diff --git a/Misc/NEWS.d/next/Library/2024-09-18-09-15-40.gh-issue-82129.GQwt3u.rst b/Misc/NEWS.d/next/Library/2024-09-18-09-15-40.gh-issue-82129.GQwt3u.rst new file mode 100644 index 00000000000000..b8661f9eeaa5c9 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-09-18-09-15-40.gh-issue-82129.GQwt3u.rst @@ -0,0 +1,2 @@ +Fix :exc:`NameError` when calling :func:`typing.get_type_hints` on a :func:`dataclasses.dataclass` created by +:func:`dataclasses.make_dataclass` with un-annotated fields.