diff -r a0a25ffdec9d Lib/traceback.py
--- a/Lib/traceback.py	Mon Dec 10 12:05:45 2012 +0100
+++ b/Lib/traceback.py	Mon Dec 10 15:30:27 2012 +0200
@@ -71,7 +71,7 @@
         n = n+1
 
 def format_tb(tb, limit=None):
-    """A shorthand for 'format_list(extract_stack(f, limit))."""
+    """A shorthand for 'format_list(extract_tb(tb, limit))'."""
     return format_list(extract_tb(tb, limit))
 
 def extract_tb(tb, limit=None):