generate pot translation file:
    xgettext --language=Python --keyword=_:1,2 -d mytest templates/index.html

    note that xgettext may fail while parsing html elements like:
     <input type="submit" value="{{ _('bla') }}" />

    try --language=Php or something.

merge against existing pot file:
    msgmerge old.po mytest.po > new.po
    mv new.po mytest.po

compile:
    msgfmt mytest.po -o locale/{lang}/LC_MESSAGES/mytest.mo
    
    (real case):
    msgfmt po/pt_BR.po -o locale/pt_BR/LC_MESSAGES/mytest.mo

run the server:
    twistd -ny server.tac