装饰器：不改变原函数的基础上，给函数增加功能的方式，称为装饰器 
   即：为已经存在的对象添加额外的功能 
装饰器其实就是一个闭包，把一个函数当做参数后返回一个替代版的函数

decos.py:
（装饰器的参数类）代码如下：

class Locker1:
    def __init__(self):
        print('locker1...')

    @staticmethod
    def acquire():
        print('locker1 acquire...')

    @staticmethod
    def unlock():
        print('locker1 unlock...')



class Locker2(Locker1):
    @staticmethod
    def acquire():
        print('locker2 acquire...')

    @staticmethod
    def unlock():
        print('locker2 unlock...')

装饰器函数 和 主程序：

# 装饰器函数：

def locker_deco(cls):
    def _deco(func):
        def __deco(*args,**kwargs):
            print('before...')
            print(func.__name__)
            cls.acquire()
            try:
                return func(*args,**kwargs)
            finally:
                cls.unlock()
            print('after...')
        return __deco
    return _deco



# 主程序：

from decos import Locker1,Locker2

class Example:
    @locker_deco(Locker1)
    def func1(self):
        print('func1...')
        return 5

    @locker_deco(Locker1)
    @locker_deco(Locker2)
    def func2(self,a,b):
        print('func2...')
        return a+b

e=Example()
e.func2(1,2)
print('****')
print(e.func2(1,2))

运行结果：

before...
__deco
locker1 acquire...
before...
func2
locker2 acquire...
func2...
locker2 unlock...
locker1 unlock...
****
before...
__deco
locker1 acquire...
before...
func2
locker2 acquire...
func2...
locker2 unlock...
locker1 unlock...
3