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

Lib/site.py

@@ -391,7 +391,7 @@ def execsitecustomize():
         import sitecustomize
     except ImportError:
         pass
-    except Exception, err:
+    except Exception as err:
         if os.environ.get("PYTHONVERBOSE"):
             raise
         sys.stderr.write(