单例模式的装饰器实现

def singleton(cls):    __instance = {}    def wrapper(x):        if cls in __instance:            return __instance[cls]        else:            __instance[cls] = cls(x)            return __instance[cls]    return wrapper# @singletonclass A:    def __init__(self,x=0):        self.x = xa1 = A(1)a2 = A(2)print(a1)print(a2)

来源：https://www.cnblogs.com/llbky/p/11321742.html