先看下object类中对__new__()方法的定义:
class object:
@staticmethod # known case of __new__
def __new__(cls, *more): # known special case of object.__new__
""" T.__new__(S, ...)...
__new__方法实现单例模式
class SingletomCls:
def __new__(cls, *args, **kwargs):
if not hasattr(cls,"_instance"):
cls._instance=super(SingletomCls, cls).__new_...