python装饰器1

Posted 2020-09-05

第八步：让装饰器带 类 参数

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# -*- coding:gbk -*- ‘‘‘示例8: 装饰器带类参数‘‘‘   class locker:     def __init__(self):         print("locker.__init__() should be not called.")               @staticmethod     def acquire():         print("locker.acquire() called.（这是静态方法）")               @staticmethod     def release():         print("  locker.release() called.（不需要对象实例）")   def deco(cls):     ‘‘‘cls 必须实现acquire和release静态方法‘‘‘     def _deco(func):         def __deco():             print("before %s called [%s]." % (func.__name__, cls))             cls.acquire()             try:                 return func()             finally:                 cls.release()         return __deco     return _deco   @deco(locker) def myfunc():     print(" myfunc() called.")   myfunc() myfunc()

第九步：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

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# -*- coding:gbk -*- ‘‘‘mylocker.py: 公共类 for 示例9.py‘‘‘   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

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# -*- 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‘‘‘   from mylocker import *   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(a.myfunc())     print(a.myfunc2(1, 2))     print(a.myfunc2(3, 4))

下面是参考资料，当初有不少地方没看明白，真正练习后才明白些：

1. Python装饰器学习 http://blog.csdn.net/thy38/article/details/4471421

2. Python装饰器与面向切面编程 http://www.cnblogs.com/huxi/archive/2011/03/01/1967600.html

3. Python装饰器的理解 http://apps.hi.baidu.com/share/detail/17572338