class python: ' '.join([x for x in ['field', field.is_required() and 'required' or None, field_has_error and 'error' or None, field.get_value('css_class') or None] if x is not None])"
class python: ' '.join([x for x in ['field', field.is_required() and 'required' or None, field_has_error and 'error' or None, field.get_value('css_class') or None] if x is not None])"