utilize yield from
diff --git a/Lib/traceback.py b/Lib/traceback.py
index eeb9e73..33b86c7 100644
--- a/Lib/traceback.py
+++ b/Lib/traceback.py
@@ -132,8 +132,7 @@
     its.append([(exc, custom_tb or exc.__traceback__)])
     # itertools.chain is in an extension module and may be unavailable
     for it in its:
-        for x in it:
-            yield x
+        yield from it
 
 
 def print_exception(etype, value, tb, limit=None, file=None, chain=True):