Unless you're using (or want to extend)  the accessors module, you need to write <code>get_*(self), set_*(self, value), and del_*(self)</code> method for each slot.  If you want read-only properties, this can be done with help from the <code>accessors.AllForbidden</code> class.  None of the accessor-generator classes will overwrite defined methods.  So, you can use the generator to make set + del forbidden, but write your own get_() method.

The accessors module is there to help you avoid having to write all three methods all the time.  Perhaps adding a "run a command" or "call a python function" accessor-generator class would be useful?  I know there are a few places in network_xml where they could be used.  It's up to you.