[Zope] How does Zope and Python work?

Consider: <dtml-in select_zsqlmethod_sql> <dtml-var foo> </dtml-in> <dtml-in select_zsqlmethod_sql> <dtml-var bar> </dtml-in> 2 process calls to select_zsqlmethod_sql() <dtml-let sequence=select_zsqlmethod_sql> <dtml-in sequence> <dtml-var foo> </dtml-in> <dtml-in sequence> <dtml-var bar> </dtml-in> </dtml-let> 1 process call, isn't it?? Is it different for calls to other sequence returning things? like objectValues() or getResultScript() or whatever. I just want to use garbage collection instead of to many calls to other objects around. Peter