目录：
- isinstance(obj,cls)和issubclass(sub,super)
- 反射
- __setattr__,__delattr__,__getattr__
- 二次加工标准类型(包装)
- __getattribute__
- 描述符(__get__,__set__,__delete__)
- property
- __setitem__,__getitem,__delitem__
- __str__,__repr__,__format__
- __slots__
- __next__和__iter__实现迭代器协议
- __doc__
- __module__和__class__
- __del__
- __enter__和__exit__
- __call__
- metaclass
一、isinstance(obj,cls)和issubclass(sub,super)
1、isinstance(obj,cls)检查是否obj是否是类 cls 的对象
1 class Foo(object): 2 pass 3 4 obj = Foo() 5 6 isinstance(obj, Foo)