class Class_1:
    str_1 = '1'
    def __init__(self, str_1 = str_1):
        self.str_1 = str_1
class Class_2(Class_1):  # 否则TypeError: Class_2.__init__() takes 1 positional argument but 2 were given
    def __init__(self, str_1):
        super().__init__(str_1)  # 否则等于没改
        print(self.str_1)
Instance = Class_2('2')