From a840465368ca5f9ab414060a91c7147dc19721ec Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Sat, 1 Apr 2023 10:23:01 +0300
Subject: [PATCH 01/17] gh-106016: Support customizing of module attributes
 access with __setattr__/__delattr__

---
 Doc/reference/datamodel.rst                   | 50 ++++++++++++-------
 Lib/test/bad_delattr.py                       |  2 +
 Lib/test/bad_delattr2.py                      |  4 ++
 Lib/test/bad_setattr.py                       |  2 +
 Lib/test/bad_setattr2.py                      |  4 ++
 Lib/test/good_delattr.py                      |  6 +++
 Lib/test/good_setattr.py                      |  6 +++
 Lib/test/test_module/__init__.py              | 47 +++++++++++++++++
 ...-08-22-09-57-59.gh-issue-106016.lpbUq8.rst |  2 +
 Objects/moduleobject.c                        | 36 ++++++++++++-
 10 files changed, 141 insertions(+), 18 deletions(-)
 create mode 100644 Lib/test/bad_delattr.py
 create mode 100644 Lib/test/bad_delattr2.py
 create mode 100644 Lib/test/bad_setattr.py
 create mode 100644 Lib/test/bad_setattr2.py
 create mode 100644 Lib/test/good_delattr.py
 create mode 100644 Lib/test/good_setattr.py
 create mode 100644 Misc/NEWS.d/next/Core and Builtins/2023-08-22-09-57-59.gh-issue-106016.lpbUq8.rst

diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index 229fa696c9142f..5a866658f0eb21 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -1695,11 +1695,15 @@ Customizing module attribute access
 
 .. index::
    single: __getattr__ (module attribute)
+   single: __setattr__ (module attribute)
+   single: __delattr__ (module attribute)
    single: __dir__ (module attribute)
    single: __class__ (module attribute)
 
-Special names ``__getattr__`` and ``__dir__`` can be also used to customize
-access to module attributes. The ``__getattr__`` function at the module level
+Special names ``__getattr__``, ``__setattr__``, ``__delattr__`` and ``__dir__``
+can be also used to customize access to module attributes.
+
+The ``__getattr__`` function at the module level
 should accept one argument which is the name of an attribute and return the
 computed value or raise an :exc:`AttributeError`. If an attribute is
 not found on a module object through the normal lookup, i.e.
@@ -1707,32 +1711,41 @@ not found on a module object through the normal lookup, i.e.
 the module ``__dict__`` before raising an :exc:`AttributeError`. If found,
 it is called with the attribute name and the result is returned.
 
+The ``__setattr__`` function should accept two arguments, respectively, the
+name of an attribute and the value to be assigned and return :const:`None` or
+raise an :exc:`AttributeError`.  If present, this function overrides the
+standard :func:`setattr` behaviour on a module.  For example::
+
+   def __setattr__(name, value):
+       print(f'Setting {name} to {value}...')
+       globals()[name] = value
+
+The ``__delattr__`` function should accept one argument which is the name of an
+attribute and return :const:`None` or raise an :exc:`AttributeError`.  If present,
+this function overrides the standard :func:`delattr` behaviour on a module.
+
 The ``__dir__`` function should accept no arguments, and return a sequence of
 strings that represents the names accessible on module. If present, this
 function overrides the standard :func:`dir` search on a module.
 
-For a more fine grained customization of the module behavior (setting
-attributes, properties, etc.), one can set the ``__class__`` attribute of
-a module object to a subclass of :class:`types.ModuleType`. For example::
+For a more fine grained customization of the module behavior, one can set the
+``__class__`` attribute of a module object to a subclass of
+:class:`types.ModuleType`. For example::
 
    import sys
    from types import ModuleType
 
-   class VerboseModule(ModuleType):
-       def __repr__(self):
-           return f'Verbose {self.__name__}'
-
-       def __setattr__(self, attr, value):
-           print(f'Setting {attr}...')
-           super().__setattr__(attr, value)
+   class CallableModule(ModuleType):
+       def __call__(self, *args, **kwargs):
+           raise RuntimeError("NO-body expects the Spanish Inquisition!")
 
-   sys.modules[__name__].__class__ = VerboseModule
+   sys.modules[__name__].__class__ = CallableModule
 
 .. note::
-   Defining module ``__getattr__`` and setting module ``__class__`` only
-   affect lookups made using the attribute access syntax -- directly accessing
-   the module globals (whether by code within the module, or via a reference
-   to the module's globals dictionary) is unaffected.
+   Defining module ``__getattr__``/``__setattr__``/``__delattr__`` and setting
+   module ``__class__`` only affect lookups made using the attribute access
+   syntax -- directly accessing the module globals (whether by code within the
+   module, or via a reference to the module's globals dictionary) is unaffected.
 
 .. versionchanged:: 3.5
    ``__class__`` module attribute is now writable.
@@ -1740,6 +1753,9 @@ a module object to a subclass of :class:`types.ModuleType`. For example::
 .. versionadded:: 3.7
    ``__getattr__`` and ``__dir__`` module attributes.
 
+.. versionadded:: 3.13
+   ``__setattr__`` and ``__delattr__`` module attributes.
+
 .. seealso::
 
    :pep:`562` - Module __getattr__ and __dir__
diff --git a/Lib/test/bad_delattr.py b/Lib/test/bad_delattr.py
new file mode 100644
index 00000000000000..5919b7dda26003
--- /dev/null
+++ b/Lib/test/bad_delattr.py
@@ -0,0 +1,2 @@
+foo = 1
+__delattr__ = "Oops"
diff --git a/Lib/test/bad_delattr2.py b/Lib/test/bad_delattr2.py
new file mode 100644
index 00000000000000..93fc7a21774f8c
--- /dev/null
+++ b/Lib/test/bad_delattr2.py
@@ -0,0 +1,4 @@
+foo = 1
+
+def __delattr__():
+    "Bad function signature"
diff --git a/Lib/test/bad_setattr.py b/Lib/test/bad_setattr.py
new file mode 100644
index 00000000000000..6b30f22f7715e6
--- /dev/null
+++ b/Lib/test/bad_setattr.py
@@ -0,0 +1,2 @@
+foo = 1
+__setattr__ = "Oops"
diff --git a/Lib/test/bad_setattr2.py b/Lib/test/bad_setattr2.py
new file mode 100644
index 00000000000000..efa28456b5e9c2
--- /dev/null
+++ b/Lib/test/bad_setattr2.py
@@ -0,0 +1,4 @@
+foo = 1
+
+def __setattr__():
+    "Bad function signature"
diff --git a/Lib/test/good_delattr.py b/Lib/test/good_delattr.py
new file mode 100644
index 00000000000000..97b29d68956c93
--- /dev/null
+++ b/Lib/test/good_delattr.py
@@ -0,0 +1,6 @@
+foo = 1
+
+def __delattr__(name):
+    if name == 'foo':
+        raise AttributeError("Read-only attribute")
+    del globals()[name]
diff --git a/Lib/test/good_setattr.py b/Lib/test/good_setattr.py
new file mode 100644
index 00000000000000..4c28d05bbbdaf0
--- /dev/null
+++ b/Lib/test/good_setattr.py
@@ -0,0 +1,6 @@
+foo = 1
+
+def __setattr__(name, value):
+    if name == 'foo':
+        raise AttributeError("Read-only attribute")
+    globals()[name] = value
diff --git a/Lib/test/test_module/__init__.py b/Lib/test/test_module/__init__.py
index cfc4d9ccf1cc81..b85ffc7f0a5ad1 100644
--- a/Lib/test/test_module/__init__.py
+++ b/Lib/test/test_module/__init__.py
@@ -150,6 +150,53 @@ def test_module_getattr_errors(self):
         if 'test.test_module.bad_getattr2' in sys.modules:
             del sys.modules['test.test_module.bad_getattr2']
 
+    def test_module_setattr(self):
+        import test.good_setattr as gsa
+        self.assertEqual(gsa.foo, 1)
+        with self.assertRaises(AttributeError):
+            gsa.bar
+        with self.assertRaisesRegex(AttributeError, "Read-only attribute"):
+            gsa.foo = 2
+        gsa.bar = 3
+        self.assertEqual(gsa.bar, 3)
+
+    def test_module_setattr_errors(self):
+        import test.bad_setattr as bsa
+        from test import bad_setattr2
+        self.assertEqual(bsa.foo, 1)
+        self.assertEqual(bad_setattr2.foo, 1)
+        with self.assertRaises(TypeError):
+            bsa.foo = 2
+        with self.assertRaises(TypeError):
+            bad_setattr2.foo = 2
+        del sys.modules['test.bad_setattr']
+        del sys.modules['test.bad_setattr2']
+
+    def test_module_delattr(self):
+        import test.good_delattr as gda
+        self.assertEqual(gda.foo, 1)
+        with self.assertRaises(AttributeError):
+            gda.bar
+        with self.assertRaisesRegex(AttributeError, "Read-only attribute"):
+            del gda.foo
+        gda.bar = 3
+        self.assertEqual(gda.bar, 3)
+        del gda.bar
+        with self.assertRaises(AttributeError):
+            gda.bar
+
+    def test_module_delattr_errors(self):
+        import test.bad_delattr as bda
+        from test import bad_delattr2
+        self.assertEqual(bda.foo, 1)
+        self.assertEqual(bad_delattr2.foo, 1)
+        with self.assertRaises(TypeError):
+            del bda.foo
+        with self.assertRaises(TypeError):
+            del bad_delattr2.foo
+        del sys.modules['test.bad_delattr']
+        del sys.modules['test.bad_delattr2']
+
     def test_module_dir(self):
         import test.test_module.good_getattr as gga
         self.assertEqual(dir(gga), ['a', 'b', 'c'])
diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-08-22-09-57-59.gh-issue-106016.lpbUq8.rst b/Misc/NEWS.d/next/Core and Builtins/2023-08-22-09-57-59.gh-issue-106016.lpbUq8.rst
new file mode 100644
index 00000000000000..17a126a5bbd592
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2023-08-22-09-57-59.gh-issue-106016.lpbUq8.rst	
@@ -0,0 +1,2 @@
+Add support for module ``__setattr__`` and ``__delattr__``. Patch by Sergey
+B Kirpichev.
diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 7e890d021cb946..abf95211c50f8c 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -866,6 +866,40 @@ _Py_module_getattro(PyModuleObject *m, PyObject *name)
     return _Py_module_getattro_impl(m, name, 0);
 }
 
+static int
+module_setattro(PyModuleObject *m, PyObject *name, PyObject *value)
+{
+    PyObject *setattr, *delattr;
+    assert(m->md_dict != NULL);
+    PyErr_Clear();
+    if (value == NULL) {
+        delattr = PyDict_GetItemWithError(m->md_dict, &_Py_ID(__delattr__));
+        if (PyErr_Occurred()) {
+            return -1;
+        }
+        if (delattr) {
+            PyObject_CallFunctionObjArgs(delattr, name, NULL);
+            if (PyErr_Occurred()) {
+                return -1;
+            }
+            return 0;
+        }
+    } else {
+        setattr = PyDict_GetItemWithError(m->md_dict, &_Py_ID(__setattr__));
+        if (PyErr_Occurred()) {
+            return -1;
+        }
+        if (setattr) {
+            PyObject_CallFunctionObjArgs(setattr, name, value, NULL);
+            if (PyErr_Occurred()) {
+                return -1;
+            }
+            return 0;
+        }
+    }
+    return PyObject_GenericSetAttr((PyObject *)m, name, value);
+}
+
 static int
 module_traverse(PyModuleObject *m, visitproc visit, void *arg)
 {
@@ -1018,7 +1052,7 @@ PyTypeObject PyModule_Type = {
     0,                                          /* tp_call */
     0,                                          /* tp_str */
     (getattrofunc)_Py_module_getattro,          /* tp_getattro */
-    PyObject_GenericSetAttr,                    /* tp_setattro */
+    (setattrofunc)module_setattro,              /* tp_setattro */
     0,                                          /* tp_as_buffer */
     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
         Py_TPFLAGS_BASETYPE,                    /* tp_flags */

From 3e78225b8847e195f15a027a8b9a4428681156ca Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Tue, 22 Aug 2023 16:03:06 +0300
Subject: [PATCH 02/17] Update Doc/reference/datamodel.rst

Co-authored-by: Victor Stinner <vstinner@python.org>
---
 Doc/reference/datamodel.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index 5a866658f0eb21..e769820a75602b 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -1742,8 +1742,8 @@ For a more fine grained customization of the module behavior, one can set the
    sys.modules[__name__].__class__ = CallableModule
 
 .. note::
-   Defining module ``__getattr__``/``__setattr__``/``__delattr__`` and setting
-   module ``__class__`` only affect lookups made using the attribute access
+   Defining module ``__getattr__``, ``__setattr__``, ``__delattr__``, ``__dir__``
+   and setting module ``__class__`` only affect lookups made using the attribute access
    syntax -- directly accessing the module globals (whether by code within the
    module, or via a reference to the module's globals dictionary) is unaffected.
 

From 0a8cec616c743a670b6ef91bc51e52a1998e23b9 Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Tue, 22 Aug 2023 16:03:22 +0300
Subject: [PATCH 03/17] Update Doc/reference/datamodel.rst

Co-authored-by: Victor Stinner <vstinner@python.org>
---
 Doc/reference/datamodel.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index e769820a75602b..c562c8d967de28 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -1712,7 +1712,7 @@ the module ``__dict__`` before raising an :exc:`AttributeError`. If found,
 it is called with the attribute name and the result is returned.
 
 The ``__setattr__`` function should accept two arguments, respectively, the
-name of an attribute and the value to be assigned and return :const:`None` or
+name of an attribute and the value to be assigned. It can
 raise an :exc:`AttributeError`.  If present, this function overrides the
 standard :func:`setattr` behaviour on a module.  For example::
 

From 2904f501f23d9259997aba74ffa9f0a41b43cf31 Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Tue, 22 Aug 2023 16:03:41 +0300
Subject: [PATCH 04/17] Update Doc/reference/datamodel.rst

Co-authored-by: Victor Stinner <vstinner@python.org>
---
 Doc/reference/datamodel.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index c562c8d967de28..1882b46547fc82 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -1721,7 +1721,7 @@ standard :func:`setattr` behaviour on a module.  For example::
        globals()[name] = value
 
 The ``__delattr__`` function should accept one argument which is the name of an
-attribute and return :const:`None` or raise an :exc:`AttributeError`.  If present,
+attribute. It can raise an :exc:`AttributeError`.  If present,
 this function overrides the standard :func:`delattr` behaviour on a module.
 
 The ``__dir__`` function should accept no arguments, and return a sequence of

From bce16674cc68f31e779120452792d64e96388518 Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Tue, 22 Aug 2023 16:09:42 +0300
Subject: [PATCH 05/17] Drop PyErr_Clear()

---
 Objects/moduleobject.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index abf95211c50f8c..a1683171bf9729 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -871,7 +871,6 @@ module_setattro(PyModuleObject *m, PyObject *name, PyObject *value)
 {
     PyObject *setattr, *delattr;
     assert(m->md_dict != NULL);
-    PyErr_Clear();
     if (value == NULL) {
         delattr = PyDict_GetItemWithError(m->md_dict, &_Py_ID(__delattr__));
         if (PyErr_Occurred()) {

From bcafd0d329e1ff9efa63c0ca41673a684a441acd Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Tue, 22 Aug 2023 16:11:30 +0300
Subject: [PATCH 06/17] move delattr/setattr declarations

---
 Objects/moduleobject.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index a1683171bf9729..5219fa34576e74 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -869,10 +869,9 @@ _Py_module_getattro(PyModuleObject *m, PyObject *name)
 static int
 module_setattro(PyModuleObject *m, PyObject *name, PyObject *value)
 {
-    PyObject *setattr, *delattr;
     assert(m->md_dict != NULL);
     if (value == NULL) {
-        delattr = PyDict_GetItemWithError(m->md_dict, &_Py_ID(__delattr__));
+        PyObject *delattr = PyDict_GetItemWithError(m->md_dict, &_Py_ID(__delattr__));
         if (PyErr_Occurred()) {
             return -1;
         }
@@ -884,7 +883,7 @@ module_setattro(PyModuleObject *m, PyObject *name, PyObject *value)
             return 0;
         }
     } else {
-        setattr = PyDict_GetItemWithError(m->md_dict, &_Py_ID(__setattr__));
+        PyObject *setattr = PyDict_GetItemWithError(m->md_dict, &_Py_ID(__setattr__));
         if (PyErr_Occurred()) {
             return -1;
         }

From 0740efb78f2c4aff4991bdb0f25acf46847bce5a Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Tue, 22 Aug 2023 16:12:48 +0300
Subject: [PATCH 07/17] m -> mod

---
 Objects/moduleobject.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 5219fa34576e74..572e0db2d755c9 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -867,11 +867,11 @@ _Py_module_getattro(PyModuleObject *m, PyObject *name)
 }
 
 static int
-module_setattro(PyModuleObject *m, PyObject *name, PyObject *value)
+module_setattro(PyModuleObject *mod, PyObject *name, PyObject *value)
 {
-    assert(m->md_dict != NULL);
+    assert(mod->md_dict != NULL);
     if (value == NULL) {
-        PyObject *delattr = PyDict_GetItemWithError(m->md_dict, &_Py_ID(__delattr__));
+        PyObject *delattr = PyDict_GetItemWithError(mod->md_dict, &_Py_ID(__delattr__));
         if (PyErr_Occurred()) {
             return -1;
         }
@@ -883,7 +883,7 @@ module_setattro(PyModuleObject *m, PyObject *name, PyObject *value)
             return 0;
         }
     } else {
-        PyObject *setattr = PyDict_GetItemWithError(m->md_dict, &_Py_ID(__setattr__));
+        PyObject *setattr = PyDict_GetItemWithError(mod->md_dict, &_Py_ID(__setattr__));
         if (PyErr_Occurred()) {
             return -1;
         }
@@ -895,7 +895,7 @@ module_setattro(PyModuleObject *m, PyObject *name, PyObject *value)
             return 0;
         }
     }
-    return PyObject_GenericSetAttr((PyObject *)m, name, value);
+    return PyObject_GenericSetAttr((PyObject *)mod, name, value);
 }
 
 static int

From 74c3d138ce75d08470e0e76571ce77424c3597c1 Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Tue, 22 Aug 2023 16:19:50 +0300
Subject: [PATCH 08/17] Check PyObject_CallFunctionObjArgs return value

---
 Objects/moduleobject.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 572e0db2d755c9..3cc316e8fc6709 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -869,6 +869,7 @@ _Py_module_getattro(PyModuleObject *m, PyObject *name)
 static int
 module_setattro(PyModuleObject *mod, PyObject *name, PyObject *value)
 {
+    PyObject *ret;
     assert(mod->md_dict != NULL);
     if (value == NULL) {
         PyObject *delattr = PyDict_GetItemWithError(mod->md_dict, &_Py_ID(__delattr__));
@@ -876,8 +877,8 @@ module_setattro(PyModuleObject *mod, PyObject *name, PyObject *value)
             return -1;
         }
         if (delattr) {
-            PyObject_CallFunctionObjArgs(delattr, name, NULL);
-            if (PyErr_Occurred()) {
+            ret = PyObject_CallFunctionObjArgs(delattr, name, NULL);
+            if (ret == NULL) {
                 return -1;
             }
             return 0;
@@ -888,8 +889,8 @@ module_setattro(PyModuleObject *mod, PyObject *name, PyObject *value)
             return -1;
         }
         if (setattr) {
-            PyObject_CallFunctionObjArgs(setattr, name, value, NULL);
-            if (PyErr_Occurred()) {
+            ret = PyObject_CallFunctionObjArgs(setattr, name, value, NULL);
+            if (ret == NULL) {
                 return -1;
             }
             return 0;

From 83c4c504dca2ee1e78c685f4507ac79f71c6bcce Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Tue, 22 Aug 2023 16:32:26 +0300
Subject: [PATCH 09/17] Document changes in the "Other Language Changes"
 section

---
 Doc/whatsnew/3.13.rst | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
index 8509e18a7d792e..0139b4284e640b 100644
--- a/Doc/whatsnew/3.13.rst
+++ b/Doc/whatsnew/3.13.rst
@@ -91,6 +91,10 @@ Other Language Changes
   of the ``optimize`` argument.
   (Contributed by Irit Katriel in :gh:`108113`).
 
+* Support customizing module attribute access with ``__setattr__`` and
+  ``__delattr__`` functions at the module level.  (Contributed by
+  Sergey B Kirpichev in :gh:`108261`).
+
 New Modules
 ===========
 

From 7fe6a06aa2070886958e8c596fdcb5df74280fca Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Tue, 22 Aug 2023 17:19:03 +0300
Subject: [PATCH 10/17] Use PyDict_GetItemRef instead of
 PyDict_GetItemWithError

---
 Objects/moduleobject.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 3cc316e8fc6709..fad39560b43fca 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -869,28 +869,31 @@ _Py_module_getattro(PyModuleObject *m, PyObject *name)
 static int
 module_setattro(PyModuleObject *mod, PyObject *name, PyObject *value)
 {
-    PyObject *ret;
+    PyObject *res;
+    int ret;
     assert(mod->md_dict != NULL);
     if (value == NULL) {
-        PyObject *delattr = PyDict_GetItemWithError(mod->md_dict, &_Py_ID(__delattr__));
-        if (PyErr_Occurred()) {
+        PyObject *delattr;
+        ret = PyDict_GetItemRef(mod->md_dict, &_Py_ID(__delattr__), &delattr);
+        if (ret == -1) {
             return -1;
         }
-        if (delattr) {
-            ret = PyObject_CallFunctionObjArgs(delattr, name, NULL);
-            if (ret == NULL) {
+        if (ret) {
+            res = PyObject_CallFunctionObjArgs(delattr, name, NULL);
+            if (res == NULL) {
                 return -1;
             }
             return 0;
         }
     } else {
-        PyObject *setattr = PyDict_GetItemWithError(mod->md_dict, &_Py_ID(__setattr__));
-        if (PyErr_Occurred()) {
+        PyObject *setattr;
+        ret = PyDict_GetItemRef(mod->md_dict, &_Py_ID(__setattr__), &setattr);
+        if (ret == -1) {
             return -1;
         }
-        if (setattr) {
-            ret = PyObject_CallFunctionObjArgs(setattr, name, value, NULL);
-            if (ret == NULL) {
+        if (ret) {
+            res = PyObject_CallFunctionObjArgs(setattr, name, value, NULL);
+            if (res == NULL) {
                 return -1;
             }
             return 0;

From 47d93ce7d16c47510cd9719f468262f1c3ae4956 Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Tue, 22 Aug 2023 18:03:59 +0300
Subject: [PATCH 11/17] Move test modules to Lib/test/test_module/

---
 Lib/test/test_module/__init__.py           | 20 ++++++++++----------
 Lib/test/{ => test_module}/bad_delattr.py  |  0
 Lib/test/{ => test_module}/bad_delattr2.py |  0
 Lib/test/{ => test_module}/bad_setattr.py  |  0
 Lib/test/{ => test_module}/bad_setattr2.py |  0
 Lib/test/{ => test_module}/good_delattr.py |  0
 Lib/test/{ => test_module}/good_setattr.py |  0
 7 files changed, 10 insertions(+), 10 deletions(-)
 rename Lib/test/{ => test_module}/bad_delattr.py (100%)
 rename Lib/test/{ => test_module}/bad_delattr2.py (100%)
 rename Lib/test/{ => test_module}/bad_setattr.py (100%)
 rename Lib/test/{ => test_module}/bad_setattr2.py (100%)
 rename Lib/test/{ => test_module}/good_delattr.py (100%)
 rename Lib/test/{ => test_module}/good_setattr.py (100%)

diff --git a/Lib/test/test_module/__init__.py b/Lib/test/test_module/__init__.py
index b85ffc7f0a5ad1..9e0458fb3b5c20 100644
--- a/Lib/test/test_module/__init__.py
+++ b/Lib/test/test_module/__init__.py
@@ -151,7 +151,7 @@ def test_module_getattr_errors(self):
             del sys.modules['test.test_module.bad_getattr2']
 
     def test_module_setattr(self):
-        import test.good_setattr as gsa
+        import test.test_module.good_setattr as gsa
         self.assertEqual(gsa.foo, 1)
         with self.assertRaises(AttributeError):
             gsa.bar
@@ -161,19 +161,19 @@ def test_module_setattr(self):
         self.assertEqual(gsa.bar, 3)
 
     def test_module_setattr_errors(self):
-        import test.bad_setattr as bsa
-        from test import bad_setattr2
+        import test.test_module.bad_setattr as bsa
+        from test.test_module import bad_setattr2
         self.assertEqual(bsa.foo, 1)
         self.assertEqual(bad_setattr2.foo, 1)
         with self.assertRaises(TypeError):
             bsa.foo = 2
         with self.assertRaises(TypeError):
             bad_setattr2.foo = 2
-        del sys.modules['test.bad_setattr']
-        del sys.modules['test.bad_setattr2']
+        del sys.modules['test.test_module.bad_setattr']
+        del sys.modules['test.test_module.bad_setattr2']
 
     def test_module_delattr(self):
-        import test.good_delattr as gda
+        import test.test_module.good_delattr as gda
         self.assertEqual(gda.foo, 1)
         with self.assertRaises(AttributeError):
             gda.bar
@@ -186,16 +186,16 @@ def test_module_delattr(self):
             gda.bar
 
     def test_module_delattr_errors(self):
-        import test.bad_delattr as bda
-        from test import bad_delattr2
+        import test.test_module.bad_delattr as bda
+        from test.test_module import bad_delattr2
         self.assertEqual(bda.foo, 1)
         self.assertEqual(bad_delattr2.foo, 1)
         with self.assertRaises(TypeError):
             del bda.foo
         with self.assertRaises(TypeError):
             del bad_delattr2.foo
-        del sys.modules['test.bad_delattr']
-        del sys.modules['test.bad_delattr2']
+        del sys.modules['test.test_module.bad_delattr']
+        del sys.modules['test.test_module.bad_delattr2']
 
     def test_module_dir(self):
         import test.test_module.good_getattr as gga
diff --git a/Lib/test/bad_delattr.py b/Lib/test/test_module/bad_delattr.py
similarity index 100%
rename from Lib/test/bad_delattr.py
rename to Lib/test/test_module/bad_delattr.py
diff --git a/Lib/test/bad_delattr2.py b/Lib/test/test_module/bad_delattr2.py
similarity index 100%
rename from Lib/test/bad_delattr2.py
rename to Lib/test/test_module/bad_delattr2.py
diff --git a/Lib/test/bad_setattr.py b/Lib/test/test_module/bad_setattr.py
similarity index 100%
rename from Lib/test/bad_setattr.py
rename to Lib/test/test_module/bad_setattr.py
diff --git a/Lib/test/bad_setattr2.py b/Lib/test/test_module/bad_setattr2.py
similarity index 100%
rename from Lib/test/bad_setattr2.py
rename to Lib/test/test_module/bad_setattr2.py
diff --git a/Lib/test/good_delattr.py b/Lib/test/test_module/good_delattr.py
similarity index 100%
rename from Lib/test/good_delattr.py
rename to Lib/test/test_module/good_delattr.py
diff --git a/Lib/test/good_setattr.py b/Lib/test/test_module/good_setattr.py
similarity index 100%
rename from Lib/test/good_setattr.py
rename to Lib/test/test_module/good_setattr.py

From f3f796dbb0d6962c2d1ae30ff052f599793f12c5 Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Wed, 23 Aug 2023 05:58:46 +0300
Subject: [PATCH 12/17] Avoid ret variable

---
 Objects/moduleobject.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index fad39560b43fca..dff8184027c1c7 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -870,15 +870,13 @@ static int
 module_setattro(PyModuleObject *mod, PyObject *name, PyObject *value)
 {
     PyObject *res;
-    int ret;
     assert(mod->md_dict != NULL);
     if (value == NULL) {
         PyObject *delattr;
-        ret = PyDict_GetItemRef(mod->md_dict, &_Py_ID(__delattr__), &delattr);
-        if (ret == -1) {
+        if (PyDict_GetItemRef(mod->md_dict, &_Py_ID(__delattr__), &delattr) < 0) {
             return -1;
         }
-        if (ret) {
+        if (delattr) {
             res = PyObject_CallFunctionObjArgs(delattr, name, NULL);
             if (res == NULL) {
                 return -1;
@@ -887,11 +885,10 @@ module_setattro(PyModuleObject *mod, PyObject *name, PyObject *value)
         }
     } else {
         PyObject *setattr;
-        ret = PyDict_GetItemRef(mod->md_dict, &_Py_ID(__setattr__), &setattr);
-        if (ret == -1) {
+        if (PyDict_GetItemRef(mod->md_dict, &_Py_ID(__setattr__), &setattr) < 0) {
             return -1;
         }
-        if (ret) {
+        if (setattr) {
             res = PyObject_CallFunctionObjArgs(setattr, name, value, NULL);
             if (res == NULL) {
                 return -1;

From f971a228d91436978fc218912d3696d9e1b4868f Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Wed, 23 Aug 2023 06:04:43 +0300
Subject: [PATCH 13/17] +Py_DECREF

---
 Objects/moduleobject.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index dff8184027c1c7..76f2dbd3656e55 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -878,9 +878,11 @@ module_setattro(PyModuleObject *mod, PyObject *name, PyObject *value)
         }
         if (delattr) {
             res = PyObject_CallFunctionObjArgs(delattr, name, NULL);
+            Py_DECREF(delattr);
             if (res == NULL) {
                 return -1;
             }
+            Py_DECREF(res);
             return 0;
         }
     } else {
@@ -890,9 +892,11 @@ module_setattro(PyModuleObject *mod, PyObject *name, PyObject *value)
         }
         if (setattr) {
             res = PyObject_CallFunctionObjArgs(setattr, name, value, NULL);
+            Py_DECREF(setattr);
             if (res == NULL) {
                 return -1;
             }
+            Py_DECREF(res);
             return 0;
         }
     }

From 68eefbdcf994f8a5c5bc0c1e09ce873b407ee957 Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Wed, 23 Aug 2023 06:25:20 +0300
Subject: [PATCH 14/17] Reorder setattr/delattr paths

---
 Objects/moduleobject.c | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 76f2dbd3656e55..f1bc35efe5db0b 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -869,16 +869,15 @@ _Py_module_getattro(PyModuleObject *m, PyObject *name)
 static int
 module_setattro(PyModuleObject *mod, PyObject *name, PyObject *value)
 {
-    PyObject *res;
     assert(mod->md_dict != NULL);
-    if (value == NULL) {
-        PyObject *delattr;
-        if (PyDict_GetItemRef(mod->md_dict, &_Py_ID(__delattr__), &delattr) < 0) {
+    if (value) {
+        PyObject *setattr;
+        if (PyDict_GetItemRef(mod->md_dict, &_Py_ID(__setattr__), &setattr) < 0) {
             return -1;
         }
-        if (delattr) {
-            res = PyObject_CallFunctionObjArgs(delattr, name, NULL);
-            Py_DECREF(delattr);
+        if (setattr) {
+            PyObject *res = PyObject_CallFunctionObjArgs(setattr, name, value, NULL);
+            Py_DECREF(setattr);
             if (res == NULL) {
                 return -1;
             }
@@ -886,13 +885,13 @@ module_setattro(PyModuleObject *mod, PyObject *name, PyObject *value)
             return 0;
         }
     } else {
-        PyObject *setattr;
-        if (PyDict_GetItemRef(mod->md_dict, &_Py_ID(__setattr__), &setattr) < 0) {
+        PyObject *delattr;
+        if (PyDict_GetItemRef(mod->md_dict, &_Py_ID(__delattr__), &delattr) < 0) {
             return -1;
         }
-        if (setattr) {
-            res = PyObject_CallFunctionObjArgs(setattr, name, value, NULL);
-            Py_DECREF(setattr);
+        if (delattr) {
+            PyObject *res = PyObject_CallFunctionObjArgs(delattr, name, NULL);
+            Py_DECREF(delattr);
             if (res == NULL) {
                 return -1;
             }

From 058412eb00edf5bdd4718be1d5a197f80de70e3c Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Thu, 24 Aug 2023 03:03:21 +0300
Subject: [PATCH 15/17] Apply suggestions from code review

Co-authored-by: Victor Stinner <vstinner@python.org>
---
 Lib/test/test_module/__init__.py | 7 +++++--
 Objects/moduleobject.c           | 3 ++-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_module/__init__.py b/Lib/test/test_module/__init__.py
index 9e0458fb3b5c20..b6c8f9f892fca0 100644
--- a/Lib/test/test_module/__init__.py
+++ b/Lib/test/test_module/__init__.py
@@ -159,6 +159,7 @@ def test_module_setattr(self):
             gsa.foo = 2
         gsa.bar = 3
         self.assertEqual(gsa.bar, 3)
+        del sys.modules['test.test_module.good_setattr']
 
     def test_module_setattr_errors(self):
         import test.test_module.bad_setattr as bsa
@@ -170,7 +171,8 @@ def test_module_setattr_errors(self):
         with self.assertRaises(TypeError):
             bad_setattr2.foo = 2
         del sys.modules['test.test_module.bad_setattr']
-        del sys.modules['test.test_module.bad_setattr2']
+        if 'test.test_module.bad_setattr2' in sys.modules:
+            del sys.modules['test.test_module.bad_setattr2']
 
     def test_module_delattr(self):
         import test.test_module.good_delattr as gda
@@ -195,7 +197,8 @@ def test_module_delattr_errors(self):
         with self.assertRaises(TypeError):
             del bad_delattr2.foo
         del sys.modules['test.test_module.bad_delattr']
-        del sys.modules['test.test_module.bad_delattr2']
+        if 'test.test_module.bad_delattr2' in sys.modules:
+            del sys.modules['test.test_module.bad_delattr2']
 
     def test_module_dir(self):
         import test.test_module.good_getattr as gga
diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index f1bc35efe5db0b..22bf561ce7aed2 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -884,7 +884,8 @@ module_setattro(PyModuleObject *mod, PyObject *name, PyObject *value)
             Py_DECREF(res);
             return 0;
         }
-    } else {
+    }
+    else {
         PyObject *delattr;
         if (PyDict_GetItemRef(mod->md_dict, &_Py_ID(__delattr__), &delattr) < 0) {
             return -1;

From 49c82c5600f9bbdb09afa6143d0a1f05356b9730 Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Thu, 24 Aug 2023 04:07:52 +0300
Subject: [PATCH 16/17] Update Lib/test/test_module/__init__.py

---
 Lib/test/test_module/__init__.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Lib/test/test_module/__init__.py b/Lib/test/test_module/__init__.py
index b6c8f9f892fca0..7018cd8304a13d 100644
--- a/Lib/test/test_module/__init__.py
+++ b/Lib/test/test_module/__init__.py
@@ -186,6 +186,7 @@ def test_module_delattr(self):
         del gda.bar
         with self.assertRaises(AttributeError):
             gda.bar
+            del sys.modules['test.test_module.good_delattr']
 
     def test_module_delattr_errors(self):
         import test.test_module.bad_delattr as bda

From cd0e4bef01c6b1c43d0fe9b9a63f536eec715266 Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Sun, 25 Feb 2024 11:36:50 +0300
Subject: [PATCH 17/17] Mention PEP in docs, like PEP 562

---
 Doc/reference/datamodel.rst | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index 0d7a743c61a034..b1f23fb953258e 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -2073,6 +2073,9 @@ For a more fine grained customization of the module behavior, one can set the
    :pep:`562` - Module __getattr__ and __dir__
       Describes the ``__getattr__`` and ``__dir__`` functions on modules.
 
+   :pep:`726` - Module __setattr__ and __delattr__
+      Proposes the ``__setattr__`` and ``__delattr__`` functions on modules.
+
 
 .. _descriptors: