problem with hack using multiple inheritance for plugins

[Bruno Desthuilliers]

massimo s. a écrit :
>> At this point, it seems too much a deep object-oriented hell to be
>> able to dig it myself. Would you help me getting some cue on the
>> problem?
> 
> Update. Now I know that:
> - every sane Python class should return <type 'instance'> after
> type(self)

Certainly not, unless you're using a pretty old Python version. 
'instance' type means old-style classes - the legacy Python object 
model, replaced some years ago with a *much* better one ('new-style' 
classes). IIRC, this (now dying) legacy object model should disappear 
with Py3K.

> - when disabling the multiple-inheritance-hack, the situation comes
> back to normal

I may be wrong here - I don't use old-style classes, and I avoid 
multiple inheritance whenever I can - but I think this may has to do 
with mixing old-style and new-style classes.

> What happens that makes the wxFrame class different from the cmd.Cmd
> class?

wxFrame is obviously a new-style class.

<side-note>
wrt/ this snippet:

    for plugin_name in self.config['plugins']:
         try:
             plugin=__import__(plugin_name)
             try:
                 print type(self)
                 eval('plugin.'+plugin_name+'Commands._plug_init(self)')
             except AttributeError:
                 pass
         except ImportError:
             pass

You may want to try this instead:

    for plugin_name in self.config['plugins']:
         try:
             plugin=__import__(plugin_name)
         except ImportError:
             # eventually do something like logging the error ?
             continue
         try:
             cmdplug = getattr(plugin, plugin_name+'Commands')
             cmdplug._plug_init(self)
         except AttributeError:
             # eventually do something like logging the error ?
             continue

</side-note>