python中的Init方法， new 方法 call 方法

new 方法实现单列模式思考

class Single:     _single = None     _single_only = None     def __init__(self, value):         self.v = value         print(self.v)      def __new__(cls, *args, **kwargs):         if Single._single:             return Single._single         else:             Single._single = super(Single, cls).__new__(cls, *args, **kwargs)             print("只执行一次")             return Single._single  s2 = Single(2) #结果报错     Single._single = super(Single, cls).__new__(cls, *args, **kwargs) TypeError: object() takes no parameters

• 报错显示 基类 object() 不接受额外参数

.......     def __new__(cls, *args, **kwargs):         if Single._single:             return Single._single         else:             Single._single = super(Single, cls).__new__(cls)  #这样继承就好了             print("只执行一次")             return Single._single