python · pablogsal · Jul 24, 2021 · Jul 24, 2021
@@ -361,7 +361,6 @@ def __init__(self, name, loader, *, origin=None, loader_state=None,
        self.origin = origin
        self.loader_state = loader_state
        self.submodule_search_locations = [] if is_package else None
-        self._uninitialized_submodules = []

        # file-location attributes
        self._set_fileattr = False
@@ -988,7 +987,6 @@ def _sanity_check(name, package, level):
 def _find_and_load_unlocked(name, import_):
    path = None
    parent = name.rpartition('.')[0]
-    parent_spec = None
    if parent:
        if parent not in sys.modules:
            _call_with_frames_removed(import_, parent)
@@ -1001,24 +999,15 @@ def _find_and_load_unlocked(name, import_):
        except AttributeError:
            msg = (_ERR_MSG + '; {!r} is not a package').format(name, parent)
            raise ModuleNotFoundError(msg, name=name) from None
-        parent_spec = parent_module.__spec__
-        child = name.rpartition('.')[2]
    spec = _find_spec(name, path)
    if spec is None:
        raise ModuleNotFoundError(_ERR_MSG.format(name), name=name)
    else:
-        if parent_spec:
-            # Temporarily add child we are currently importing to parent's
-            # _uninitialized_submodules for circular import tracking.
-            parent_spec._uninitialized_submodules.append(child)
-        try:
-            module = _load_unlocked(spec)
-        finally:
-            if parent_spec:
-                parent_spec._uninitialized_submodules.pop()
+        module = _load_unlocked(spec)
    if parent:
        # Set the module as an attribute on its parent.
        parent_module = sys.modules[parent]
+        child = name.rpartition('.')[2]
        try:
            setattr(parent_module, child, module)
        except AttributeError:

@@ -1350,16 +1350,6 @@ def test_circular_from_import(self):
            str(cm.exception),
        )

-    def test_absolute_circular_submodule(self):
-        with self.assertRaises(AttributeError) as cm:
-            import test.test_import.data.circular_imports.subpkg2.parent
-        self.assertIn(
-            "cannot access submodule 'parent' of module "
-            "'test.test_import.data.circular_imports.subpkg2' "
-            "(most likely due to a circular import)",
-            str(cm.exception),
-        )
-
    def test_unwritable_module(self):
        self.addCleanup(unload, "test.test_import.data.unwritable")
        self.addCleanup(unload, "test.test_import.data.unwritable.x")

diff --git a/Misc/NEWS.d/next/Core and Builtins/2021-07-23-01-52-13.bpo-44717.-vVmAh.rst b/Misc/NEWS.d/next/Core and Builtins/2021-07-23-01-52-13.bpo-44717.-vVmAh.rst
@@ -739,30 +739,6 @@ _PyModuleSpec_IsInitializing(PyObject *spec)
    return 0;
 }

-/* Check if the submodule name is in the "_uninitialized_submodules" attribute
-   of the module spec.
- */
-int
-_PyModuleSpec_IsUninitializedSubmodule(PyObject *spec, PyObject *name)
-{
-    if (spec == NULL) {
-         return 0;
-    }
-
-    _Py_IDENTIFIER(_uninitialized_submodules);
-    PyObject *value = _PyObject_GetAttrId(spec, &PyId__uninitialized_submodules);
-    if (value == NULL) {
-        return 0;
-    }
-
-    int is_uninitialized = PySequence_Contains(value, name);
-    Py_DECREF(value);
-    if (is_uninitialized == -1) {
-        return 0;
-    }
-    return is_uninitialized;
-}
-
 static PyObject*
 module_getattro(PyModuleObject *m, PyObject *name)
 {
@@ -797,12 +773,6 @@ module_getattro(PyModuleObject *m, PyObject *name)
                            "(most likely due to a circular import)",
                            mod_name, name);
        }
-        else if (_PyModuleSpec_IsUninitializedSubmodule(spec, name)) {
-            PyErr_Format(PyExc_AttributeError,
-                            "cannot access submodule '%U' of module '%U' "
-                            "(most likely due to a circular import)",
-                            name, mod_name);
-        }
        else {
            PyErr_Format(PyExc_AttributeError,
                            "module '%U' has no attribute '%U'",