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/asynchat.py b/Lib/asynchat.py
index 6f99ba1..1ad3161 100644
--- a/Lib/asynchat.py
+++ b/Lib/asynchat.py
@@ -87,7 +87,7 @@
 
         try:
             data = self.recv (self.ac_in_buffer_size)
-        except socket.error, why:
+        except socket.error as why:
             self.handle_error()
             return
 
@@ -220,7 +220,7 @@
                 if num_sent:
                     self.ac_out_buffer = self.ac_out_buffer[num_sent:]
 
-            except socket.error, why:
+            except socket.error as why:
                 self.handle_error()
                 return