[storm] grouping where results

[Javier Marcon]

Hello, I want to make a grouped condition but I don find how to do it. I
want to get this sql:

SELECT Persona.nombre, Persona.apellido, Persona.email, Persona.edad,
persona.casado
FROM Persona WHERE Persona.casado = %s AND ((Persona.nombre = %s and
Persona.edad = %s) or Persona.edad = %s) ORDER BY Persona.patente

I made this code but it lacks the last condition grouping:

                params = []
                if nombre is not None:
                        params.append( Persona.nombre == unicode(nombre) )
                if apellido is not None:
                        params.append( Persona.apellido ==
unicode(apellido) )
                if condiciones is not None:
                        cond = Or(And(Persona.nombre == u'Pepe',
Persona.edad == 20),
                            Persona.edad == 25)
                        params.append( *condiciones )
                if params:
                        resultado = store.find(Persona, And(*params))
                else:
                        resultado = store.find(Persona)

How can I do it?

Thanks,

Javier.