python的这个代码太牛了

python_nested_decorator.py

# -*- coding:gbk -*-
'''
原地址 http://www.cnblogs.com/rhcad/archive/2011/12/21/2295507.html
可以尝试了解嵌套的装饰器的原理

mylocker.py: 公共类 for 示例9.py 稍稍修改的示例9
'''
 
class mylocker:
    def __init__(self):
        print("mylocker.__init__() called.")
         
    @staticmethod
    def acquire():
        print("mylocker.acquire() called.")
         
    @staticmethod
    def unlock():
        print("  mylocker.unlock() called.")
 
class lockerex(mylocker):
    @staticmethod
    def acquire():
        print("lockerex.acquire() called.")
         
    @staticmethod
    def unlock():
        print("  lockerex.unlock() called.")
 
def lockhelper(cls):
    '''cls 必须实现acquire和release静态方法'''
    def _deco(func):
        def __deco(*args, **kwargs):
            print("before %s called." % func.__name__)
            cls.acquire()
            try:
                return func(*args, **kwargs)
            finally:
                cls.unlock()
        return __deco
    return _deco

# -*- coding:gbk -*-
'''示例9: 装饰器带类参数，并分拆公共类到其他py文件中
同时演示了对一个函数应用多个装饰器'''
 
 
class example:
    # @lockhelper(mylocker)
    def myfunc(self):
        print(" myfunc() called.")
 
    # @lockhelper(mylocker)
    # @lockhelper(lockerex)
    def myfunc2(self, a, b):
        print(" myfunc2() called.")
        return a + b
 
if __name__=="__main__":
    a = example()
    # a.myfunc()

    # print "\n\n\n"

    # print(a.myfunc())
    # print lockhelper(mylocker)(a.myfunc)()
    
    
    # print "\n\n\n"
    #print(a.myfunc2(1, 2))
    print lockhelper(mylocker)( lockhelper(lockerex)(a.myfunc2) )(1,2)
    
'''
before myfunc called.
mylocker.acquire() called.
 myfunc() called.
  mylocker.unlock() called.
None



before __deco called.
mylocker.acquire() called.
before myfunc2 called.
lockerex.acquire() called.
 myfunc2() called.
  lockerex.unlock() called.
  mylocker.unlock() called.
3
'''