From 2674c322c6cc5a81ce54d807c64cb0e221521786 Mon Sep 17 00:00:00 2001
From: Stelar <90330577+StelarDream@users.noreply.github.com>
Date: Wed, 29 Apr 2026 01:50:53 +0200
Subject: [PATCH] gh-149119: docs: mention that sentinel does not support
 subclassing (#149120)

Add note about sentinel objects not supporting subclassing

Clarify that sentinel objects do not support subclassing.
---
 Doc/library/functions.rst | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index aa99d198e436..06fd5cdc7be2 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -1839,6 +1839,8 @@ are always available.  They are listed here in alphabetical order.
    Sentinel objects are truthy and compare equal only to themselves.  They are
    intended to be compared with the :keyword:`is` operator.
 
+   ``sentinel`` does not support subclassing.
+
    Shallow and deep copies of a sentinel object return the object itself.
 
    Sentinels are conventionally assigned to a variable with a matching name.
-- 
2.47.3