Automatically loading and initialising objects from a plugins directory

[Dave Challis]

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Fredrik Lundh wrote:
> so now you're no longer supporting mixins and multiple-level
> inheritance?  why not just tweak Diez' example a little:
> 
> for name in dir(plugin):
> 
>     thing = getattr(plugin, name)
> 
>     # make sure this is a plugin
>     try:
>        if thing is Plugin:
>            continue
>        if not issubclass(thing, Plugin):
>            continue
>     except ValueError: # issubclass sucks
>        continue # not a class
> 
>     thing() # probably needs error handling around this
> 
> (I also moved the thing call out of the thing validation part, to allow
> you to distinguish between ValueErrors caused by issubclass and errors
> caused by things)
> 
> (btw, another approach would be to use a metaclass to make Plugin
> classes register themselves on import)
> 
> </F>

Thanks, that works much better.  I've only been using python a couple of
months, so still getting to grips with how it treats classes/subclasses.

I'll have a look into metaclasses too, haven't stumbled upon those yet
at all.

Cheers,
Dave

- --
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                              )        <><
             <><              (
      Dave Challis            )
____dsc at ecs.soton.ac.uk_______(___________________________________________
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