property() usage - is this as good as it gets?

[Christian Heimes]

David Moss wrote:
> Hi,
> 
> I want to manage and control access to several important attributes in
> a class and override the behaviour of some of them in various
> subclasses.
> 
> Below is a stripped version of how I've implemented this in my current
> bit of work.
> 
> It works well enough, but I can't help feeling there a cleaner more
> readable way of doing this (with less duplication, etc).
> 
> Is this as good as it gets or can this be refined and improved
> especially if I was to add in a couple more attributes some fairly
> complex over-ride logic?

The extended property type in Python 2.6 makes it much easier to 
overwrite the getter, sett or deleter of a property:

http://docs.python.org/dev/library/functions.html?highlight=property#property

class C(object):
     def __init__(self): self._x = None

     @property
     def x(self):
         """I'm the 'x' property."""
         return self._x

     @x.setter
     def x(self, value):
         self._x = value

     @x.deleter
     def x(self):
         del self._x

class D(C):
     @C.x.getter
     def x(self):
         return 2 * self._x

     @x.setter
     def x(self, value):
         self._x = value // 2

Christian