Update index.md

prochac · encukou · commit f1e640125fea · 2019-07-01T15:08:50.000+02:00
diff --git a/lessons/fast-track/str/index.md b/lessons/fast-track/str/index.md
@@ -159,7 +159,7 @@ Zkus se zamyslet, jak Python zpracuje tyto výrazy:
 
 ```pycon
 >>> len('Ola'.upper())
-4
+3
 ```
 
 ```pycon
