Jason Swails於 2013年1月31日星期四UTC+8上午8時34分03秒寫道: > Hello, > > > I was having some trouble understanding decorators and inheritance and all > that. This is what I was trying to do: > > > > # untested > class A(object): > def _protector_decorator(fcn): > > def newfcn(self, *args, **kwargs): > return fcn(self, *args, **kwargs) > return newfcn > > > > @_protector_decorator > def my_method(self, *args, **kwargs): > """ do something here """ > > > > class B(A): > def _protector_decorator(fcn): > def newfcn(self, *args, **kwargs): > > raise MyException('I do not want B to be able to access the > protected functions') > return newfcn > > > > The goal of all that was to be able to change the behavior of my_method > inside class B simply by redefining the decorator. Basically, what I want is > B.my_method() to be decorated by B._protector_decorator, but in the code I'm > running it's decorated by A._protector_decorator. > > > > I presume this is because once the decorator is applied to my_method in class > A, A.my_method is immediately bound to the new, 'decorated' function, which > is subsequently inherited (and not decorated, obviously), by B. > > > > Am I correct here? My workaround was to simply copy the method from class A > to class B, after which B._protector_decorator decorated the methods in B. > While this doesn't make the use of decorators completely pointless (the > decorators actually do something in each class, it's just different), it does > add a bunch of code duplication which I was at one point hopeful to avoid. > > > > I'm still stumbling around with decorators a little, but this exercise has > made them a lot clearer to me. > > > Thanks! > Jason
It sounds that you need a decorator mapper to perform the functionality of your designs. -- http://mail.python.org/mailman/listinfo/python-list