def?__init__(self,kind?=?"cheese"): ????????self.set_kind(kind) ????????return def?set_kind(self,kind):? ????possible_ingredients?=?self.__known_kinds(kind) ????if?possible_ingredients?==?False: ????????return?False ????else: ????????self.kind?=?kind ????????self.needed_ingredients?=?possible_ingredients以上代碼都是Omelet類中的函數(shù)AttributeError: 'Omelet' object has no attribute '_Omelet__known_kinds'如此報(bào)錯(cuò)求助?。ň瞎ヾef __known_kinds(self,kind):??????????? if kind == "cheese":??????????????? return{"eggs":2,"milk":1,"cheese":1}??????????? elif kind == "mushroom":??????????????? return{"eggs":2,"milk":1,"cheese":1,"mushroom":2}??????????? elif kind == "onion":??????????????? return{"eggs":2,"milk":1,"cheese":1,"onion":1}??????????? else:??????????????? return False