[J Cameron Cooper]

...

I'm a beginner of Zope, and feel that DTML is not so powerful to develop my custom application.

It's not. And it shouldn't be. DTML, in fact, may be too powerful

+1 I only use a tiny subset of DTML's capabilities, and farm out to Python for any serious computing. But that does not mean that DTML is useless. It is very good, but use it for its strengths, which are to format html output, and to orchestrate the sending of data to the actors that are well-suited to deal with it. For example, do not try to have a Python script create HTML for you. Instead, let it return, say, a Python list or dictionary, and have DTML produce the HTML from that - a perfect division of labor. Cheers, Tom P