摘要：
模仿《python 3 patterns》写单例，我是python2.71、内部类实现方式class OnlyOne: class __OnlyOne: def __init__(self,arg): self.val=arg def __str__(self): return self.val instance =None def __init__(self,arg): if not OnlyOne.instance: OnlyOne.instance=OnlyOne... 阅读全文
