Genshi and Peewee: how do I execute sql during generation

Question

I am trying to generate a html file with genshi

<li py:for="item in items"> 
    ${item.name}
    <ul>
        <?python 
            subc = list(item.subitems())
        ?>
        <li py:for="it in subc"> 
                ${it.name}
        </li>
    </ul>
  </li>

I get an error (unexpected EOF while parsing in expression "iter(subc)". Item is a peewee class, where i defined subitems(). Is it possible to use genshi this way, so that I don't have to create a tree with all the results first?

I have already used item.subitems() elsewhere. If I write a small app that print all on the fly, it works.

edit: it works. there was a parenthesis near subc. I won't delete this question, hoping that more people will see the power of peewee and genshi