Wiebke Pätzold wrote: ... > import Mk4py I'm not experienced in this package, so I'm not sure this will work and can't test, but: > def __call__(self, row): > try: > nachname = row.Nachname Just change this to whatever = getattr(row, self.attributeName) Where self.attributeName can be any string, e.g. defaulting to 'Nachname' if you wish, as set e.g. in __init__. Alex