__class__可理解为对象所属的父类
class A:
def __init__(self,url):
self.url = url
def out(self):
return self.url
a = A('news.163.com')
print a.out()
b = a.__class__('www.bccn.net')
print b.out()
print A
print a.__class__
a.__class__等价于A
元类的理解,
http://www.jb51.net/article/61138.htm