[Zope] dtml-in sql => dtml-in anything?

Is it possible to replace an existing ZSQL method with an identical Python External Method that behaves exactly the same way? So if I have a ZSQL method "GetThingFromDB" <dtml-in GetStuffFromDB> got a <dtml-var thing> </dtml-in> Can I replace "GetThingFromDB" with a Python External Method? I've discovered that if I return a list, then that list gets returned one item at a time. But what value does each item have? I'd like to just have the external method return exactly the same thing as the ZSQL, but I'm having some problem finding what format (if any) that is. Is this sort of thing even possible? Thanks, JJ