gh-149083: Use `sentinel` in `functools.rst` docs (#149176)

diff --git a/Doc/library/functools.rst b/Doc/library/functools.rst
index 265610db3caabd5ffc19d87aa688bbf90e989af6..7da59cba5170b35b0a0f6fa77fff39c08c8d4dc5 100644 (file)
--- a/Doc/library/functools.rst
+++ b/Doc/library/functools.rst
@@ -468,7 +468,7 @@ The :mod:`!functools` module defines the following functions:
 
    Roughly equivalent to::
 
-      initial_missing = object()
+      initial_missing = sentinel('initial_missing')
 
       def reduce(function, iterable, /, initial=initial_missing):
           it = iter(iterable)