From 2f6c5aa989a2ff506ef0b714c949f5ded8b2c088 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Mon, 1 Sep 2025 15:18:50 +0200
Subject: [PATCH 1/3] fully implement GC protocol for `random.Random`

---
 Modules/_randommodule.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/Modules/_randommodule.c b/Modules/_randommodule.c
index 2f4f388ce1161a..8e45f230b8be88 100644
--- a/Modules/_randommodule.c
+++ b/Modules/_randommodule.c
@@ -572,6 +572,12 @@ random_init(PyObject *self, PyObject *args, PyObject *kwds)
     return random_seed(RandomObject_CAST(self), arg);
 }
 
+static int
+random_traverse(PyObject *op, visitproc visit, void *arg)
+{
+    Py_VISIT(Py_TYPE(op));
+    return 0;
+}
 
 static PyMethodDef random_methods[] = {
     _RANDOM_RANDOM_RANDOM_METHODDEF
@@ -590,16 +596,15 @@ static PyType_Slot Random_Type_slots[] = {
     {Py_tp_methods, random_methods},
     {Py_tp_new, PyType_GenericNew},
     {Py_tp_init, random_init},
-    {Py_tp_free, PyObject_Free},
+    {Py_tp_traverse, random_traverse},
     {0, 0},
 };
 
 static PyType_Spec Random_Type_spec = {
-    "_random.Random",
-    sizeof(RandomObject),
-    0,
-    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
-    Random_Type_slots
+    .name = "_random.Random",
+    .basicsize = sizeof(RandomObject),
+    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,
+    .slots = Random_Type_slots
 };
 
 PyDoc_STRVAR(module_doc,

From 488be06544ee5ada166607677470c1ee2794312a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Tue, 2 Sep 2025 10:20:40 +0200
Subject: [PATCH 2/3] make random.Random immutable instead of supporting full
 GC

---
 Modules/_randommodule.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/Modules/_randommodule.c b/Modules/_randommodule.c
index 8e45f230b8be88..aa2fd28c232f28 100644
--- a/Modules/_randommodule.c
+++ b/Modules/_randommodule.c
@@ -572,12 +572,6 @@ random_init(PyObject *self, PyObject *args, PyObject *kwds)
     return random_seed(RandomObject_CAST(self), arg);
 }
 
-static int
-random_traverse(PyObject *op, visitproc visit, void *arg)
-{
-    Py_VISIT(Py_TYPE(op));
-    return 0;
-}
 
 static PyMethodDef random_methods[] = {
     _RANDOM_RANDOM_RANDOM_METHODDEF
@@ -596,14 +590,18 @@ static PyType_Slot Random_Type_slots[] = {
     {Py_tp_methods, random_methods},
     {Py_tp_new, PyType_GenericNew},
     {Py_tp_init, random_init},
-    {Py_tp_traverse, random_traverse},
+    {Py_tp_free, PyObject_Free},
     {0, 0},
 };
 
 static PyType_Spec Random_Type_spec = {
     .name = "_random.Random",
     .basicsize = sizeof(RandomObject),
-    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,
+    .flags = (
+        Py_TPFLAGS_DEFAULT
+        | Py_TPFLAGS_BASETYPE
+        | Py_TPFLAGS_IMMUTABLETYPE
+    ),
     .slots = Random_Type_slots
 };
 

From 2068b50d9a902e39a00bbe736bf1e7174a2cec22 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Tue, 2 Sep 2025 10:23:22 +0200
Subject: [PATCH 3/3] blurb

---
 .../next/Library/2025-09-02-10-23-09.gh-issue-116946.U6RpwK.rst | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2025-09-02-10-23-09.gh-issue-116946.U6RpwK.rst

diff --git a/Misc/NEWS.d/next/Library/2025-09-02-10-23-09.gh-issue-116946.U6RpwK.rst b/Misc/NEWS.d/next/Library/2025-09-02-10-23-09.gh-issue-116946.U6RpwK.rst
new file mode 100644
index 00000000000000..015cf24c8869f8
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-09-02-10-23-09.gh-issue-116946.U6RpwK.rst
@@ -0,0 +1,2 @@
+The :class:`!_random.Random` C type is now immutable. Patch by Bénédikt
+Tran.