Use string.ascii_letters instead of string.letters (SF bug #226706).
diff --git a/Mac/Tools/IDE/PyEdit.py b/Mac/Tools/IDE/PyEdit.py
index 10f583f..d8539c1 100644
--- a/Mac/Tools/IDE/PyEdit.py
+++ b/Mac/Tools/IDE/PyEdit.py
@@ -25,8 +25,7 @@
haveThreading = Wthreading.haveThreading
_scriptuntitledcounter = 1
-# _wordchars = string.letters + string.digits + "_"
-_wordchars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_'
+_wordchars = string.ascii_letters + string.digits + "_"
runButtonLabels = ["Run all", "Stop!"]