SF patch 1631942 by Collin Winter:
(a) "except E, V" -> "except E as V"
(b) V is now limited to a simple name (local variable)
(c) V is now deleted at the end of the except block
diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py
index 2ffd2f8..30df034 100644
--- a/Lib/test/test_generators.py
+++ b/Lib/test/test_generators.py
@@ -1554,7 +1554,7 @@
... while True:
... try:
... print (yield)
-... except ValueError,v:
+... except ValueError as v:
... print "caught ValueError (%s)" % (v),
>>> import sys
>>> g = f()