Replacing Axiom Lists with a new list of Items

In Axiom, is there any quick way to update the contents of one List  
with the contents of another, so that existing items can be updated,  
non existing ones deleted, and new ones added?

The best I can come up with is something like this (excuse my Potato  
Programming... I still haven't become fluent in Python). In this  
case, "oldlist" is a List of Items and "newlist" contains objects  
which aren't Items, but hold the same attributes (there are actually  
Twisted pb.RemoteCopy's). Assume my Item class has an "update" method  
that will take these objects from "newlist" and copy the attirbutes  
across.

         done = []
         for o in newlist:
             if o.storeID:
                 i = store.getItemByID(o.storeID)
                 i.update(o)
             else:
                 oldlist.append(SomeItem(store=store, ....))
             done.append(o.storeID)

         for o in oldlist:
             if o.storeID not in done:
                 oldlist.remove(o)

This works, but I am just wondering if there was a better way?

Robert