from math import pi as pi class Kreis_gettattr: def __init__(self, radius): self.radius = radius self.operators ={ 'durchmesser': lambda x: self.radius * 2 'umfang': lambda x: self.durchmesser * pi 'flaeche': lambda: x: self.radius**2 *pi } def __getattr(self, name): if name not in self.operators: raise TypeError(f'unbekannte Operation {name}') return { } [name]