Return a string representation of a patsy ModelDesc object

def _modeldesc_from_dict(self, d):
        """Return a string representation of a patsy ModelDesc object"""
        lhs_termlist = [Term([LookupFactor(d['lhs_termlist'][0])])]
        rhs_termlist = []
        for name in d['rhs_termlist']:
            if name == '':
                rhs_termlist.append(Term([]))
            else:
                rhs_termlist.append(Term([LookupFactor(name)]))

        md = ModelDesc(lhs_termlist, rhs_termlist)
        return md