[web2py] How to perform a function in a template?

[thstart]

I need to perform a function in a template, something like this:

  {{for name_first in names_first:}}
        <br>
        {{=name_first[0]}}
        <br>
        {{*urllib.quote_plus*(name_first[0])}}
        <br>
        {{=name_first[1]}}    
    {{pass}}

How to do that?