python基础之单例设计模式

Posted 2021-01-18 Jary

class Player():
    instance = None
    init_flag = False

    def __init__(self):

        if self.init_flag is False:
            print("初始化...")
            self.init_flag = True

    def __new__(cls, *args, **kwargs):
        if cls.instance is None:
            cls.instance = super().__new__(cls)
        return cls.instance

if __name__ == ‘__main__‘:
    p1 = Player()
    p2 = Player()
    p3 = Player()
    p4 = Player()
    print(p1)
    print(p2)
    print(p3)
    print(p4)

整体思路，用一个类属性来记录是否已经执行过这个函数，如果执行过了，改下类属性的值，然后判断这个值来进行单例模式