def inject_check(method): def my_method(*args): print "before" method(*args) print "after" return my_method############################ #class Demo(object):# def hello(self):# pri迹绩管啃攮救归寻害默nt "hello"# hello=inject_check(hello)########################## class Demo(object): @inject_check def hello(self): print "hello" d = Demo()d.hello()就是在函数上加个包装，如上面代码中的hello函数加上@inject_check装饰器，等价于将函数hello重新赋值：hello=inject_check(hello)