[3.12] Docs: make a tutorial example more precise (GH-125066) (GH-125079)

Docs: make a tutorial example more precise (GH-125066)

Based on discussion here:

(cherry picked from commit 6e3c70c61bf961e55e9912a31ca11f61c8e2cd0c)


https: //discuss.python.org/t/omission-in-the-documentation/66816

Co-authored-by: Ned Batchelder <ned@nedbatchelder.com>