什么是python新式类

# newstyle.py,python环境为2.xclass Classic:
    """
    python2.x默认类为经典类
    由于__getatt__ 与 __getattribute__功能效果一样，这里只用__getattr__演示
    """
    def __getattr__(self, method_name):
        print("call Classic __getattr__,it would call built-in[%s] method " % method_name)                return getattr(self.__name,method_name)class NewStyleClass(object):    def __init__(self):
        self.__name = "newstyle name"
    """
    python2.x需要指明为新式类，python3.x默认为新式类
    """
    def __getattr__(self, item):
        print("call NewStyle __getattr__,it would call built-in[%s] method " %item)                return getattr(self.__name,item)def test_dir():
    C = Classic()
    N = NewStyleClass()
    print(dir(C)        # 经典类内置有__getattr__方法
    print(dir(N)        # 新式类的内置方法继承object对象>>> python newstyle.py