*PLEASE* try to avoid sending HTML-formatted messages to the mailing list. Netscape Mail crashed three times while I tried to write this reply to your message. "David C. Morrill" wrote: : Are the Python Methods you create supposed to be methods or functions? Both. Actually, they act exactly like External Methods, so the <dtml-var> behavior you describe is normal. : I get the error message: : Error Type: TypeError : Error Value: len() of unsized object You've uncovered a bug :-P It was easy to squish, and as you discovered, it can be avoided by declaring at least one parameter with a default value. : Also, it would be nice if the 'TryIt' tab allowed you to enter arguments, like a Z SQL Method does. I agree; Feel free to contribute a patch <wink>. It's on the To-Do list.