Cast into custom type

[Henning Bredel]

Hi,

I created a plugin mechanism for my application orientating
at the mechanism described by Martin Alchy in

  http://martyalchin.com/2008/jan/10/simple-plugin-framework/

Now I'd like to call methods like `initialize(parent)' when
the user chooses to use a plugin. As described in the blog
mentioned above, I only have access to the general type called
`PluginMount' (holding all the actual plugin instances).

I tried to define "abstract" methods in PluginMount type 
raising a `NotImplementedError' but it seems, there is no
late binding (similar to Java), so the right method would be
called. Only the message 

  TypeError: unbound method initialize() must be called 
  with GeoCache instance as first argument (got PluginMount 
  instance instead)

`GeoCache' would be the plugin type. What is strange, is the
fact, that when asking what instances are hold by PluginMount

   [<class 'geocacheplugin.GeoCache'>]

is listed. So it seems, that no late binding is applied when
calling the `initialize(self, parent)' method.

I'm quite new using Python, so this might be a quite basic 
question caused by some misunderstandings in general. Feel
free to point me to appropriate site to solve my problem.

Thanks in advance.

  Henning