bpo-40552 Add 'users' variable in code sample (tutorial 4.2). (GH-19992)

* Add 'users' variable in code sample.

* 📜🤖 Added by blurb_it.

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
diff --git a/Doc/tutorial/controlflow.rst b/Doc/tutorial/controlflow.rst
index f05f5ed..26de866 100644
--- a/Doc/tutorial/controlflow.rst
+++ b/Doc/tutorial/controlflow.rst
@@ -70,6 +70,9 @@
 be tricky to get right.  Instead, it is usually more straight-forward to loop
 over a copy of the collection or to create a new collection::
 
+    # Create a sample collection
+    users = {'Hans': 'active', 'Éléonore': 'inactive', '景太郎': 'active'}
+
     # Strategy:  Iterate over a copy
     for user, status in users.copy().items():
         if status == 'inactive':