gh-65961: Raise DeprecationWarning when __package__ differs from __spec__.parent (#97879)

Also remove `importlib.util.set_package()` which was already slated for removal.

Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>

Lib/importlib/_bootstrap.py

@@ -1228,7 +1228,7 @@ def _calc___package__(globals):
         if spec is not None and package != spec.parent:
             _warnings.warn("__package__ != __spec__.parent "
                            f"({package!r} != {spec.parent!r})",
-                           ImportWarning, stacklevel=3)
+                           DeprecationWarning, stacklevel=3)
         return package
     elif spec is not None:
         return spec.parent

Lib/importlib/util.py

@@ -141,26 +141,6 @@ def _module_to_load(name):
         module.__initializing__ = False
 
 
-def set_package(fxn):
-    """Set __package__ on the returned module.
-
-    This function is deprecated.
-
-    """
-    @functools.wraps(fxn)
-    def set_package_wrapper(*args, **kwargs):
-        warnings.warn('The import system now takes care of this automatically; '
-                      'this decorator is slated for removal in Python 3.12',
-                      DeprecationWarning, stacklevel=2)
-        module = fxn(*args, **kwargs)
-        if getattr(module, '__package__', None) is None:
-            module.__package__ = module.__name__
-            if not hasattr(module, '__path__'):
-                module.__package__ = module.__package__.rpartition('.')[0]
-        return module
-    return set_package_wrapper
-
-
 def set_loader(fxn):
     """Set __loader__ on the returned module.
 

Lib/test/test_importlib/import_/test___package__.py

@@ -74,8 +74,8 @@ class Using__package__:
         self.assertEqual(module.__name__, 'pkg')
 
     def test_warn_when_package_and_spec_disagree(self):
-        # Raise an ImportWarning if __package__ != __spec__.parent.
-        with self.assertWarns(ImportWarning):
+        # Raise a DeprecationWarning if __package__ != __spec__.parent.
+        with self.assertWarns(DeprecationWarning):
             self.import_module({'__package__': 'pkg.fake',
                                 '__spec__': FakeSpec('pkg.fakefake')})
 

Lib/test/test_importlib/test_util.py

@@ -252,69 +252,6 @@ class ModuleForLoaderTests:
  ) = util.test_both(ModuleForLoaderTests, util=importlib_util)
 
 
-class SetPackageTests:
-
-    """Tests for importlib.util.set_package."""
-
-    def verify(self, module, expect):
-        """Verify the module has the expected value for __package__ after
-        passing through set_package."""
-        fxn = lambda: module
-        wrapped = self.util.set_package(fxn)
-        with warnings.catch_warnings():
-            warnings.simplefilter('ignore', DeprecationWarning)
-            wrapped()
-        self.assertTrue(hasattr(module, '__package__'))
-        self.assertEqual(expect, module.__package__)
-
-    def test_top_level(self):
-        # __package__ should be set to the empty string if a top-level module.
-        # Implicitly tests when package is set to None.
-        module = types.ModuleType('module')
-        module.__package__ = None
-        self.verify(module, '')
-
-    def test_package(self):
-        # Test setting __package__ for a package.
-        module = types.ModuleType('pkg')
-        module.__path__ = ['<path>']
-        module.__package__ = None
-        self.verify(module, 'pkg')
-
-    def test_submodule(self):
-        # Test __package__ for a module in a package.
-        module = types.ModuleType('pkg.mod')
-        module.__package__ = None
-        self.verify(module, 'pkg')
-
-    def test_setting_if_missing(self):
-        # __package__ should be set if it is missing.
-        module = types.ModuleType('mod')
-        if hasattr(module, '__package__'):
-            delattr(module, '__package__')
-        self.verify(module, '')
-
-    def test_leaving_alone(self):
-        # If __package__ is set and not None then leave it alone.
-        for value in (True, False):
-            module = types.ModuleType('mod')
-            module.__package__ = value
-            self.verify(module, value)
-
-    def test_decorator_attrs(self):
-        def fxn(module): pass
-        with warnings.catch_warnings():
-            warnings.simplefilter('ignore', DeprecationWarning)
-            wrapped = self.util.set_package(fxn)
-        self.assertEqual(wrapped.__name__, fxn.__name__)
-        self.assertEqual(wrapped.__qualname__, fxn.__qualname__)
-
-
-(Frozen_SetPackageTests,
- Source_SetPackageTests
- ) = util.test_both(SetPackageTests, util=importlib_util)
-
-
 class SetLoaderTests:
 
     """Tests importlib.util.set_loader()."""