Python plugin loader.

loader-gist.py

def load_plugin(target, invoke_on_load=True, invoke_args=(),
                invoke_kwargs={}):

    if ':' in target:
        module_name, attr_name = target.rsplit(':', 1)
    else:
        module_name, attr_name = target.rsplit('.', 1)

    try:
        module = import_module(module_name)
        attr = getattr(module, attr_name)
    except (ImportError, AttributeError) as e:
        exc = ResourceNotFound(Plugin, e, target=target)
        log.warning(exc)
        raise exc

    log.info('Loaded plugin %s', target)

    plugin = Plugin()
    plugin.module = module_name
    plugin.attr = attr_name
    plugin.path = module.__file__

    if invoke_on_load:
        log.info('Invoking plugin %s with args %s and kwargs %s',
            target, invoke_args, invoke_kwargs)
        plugin.obj = attr(*invoke_args, **invoke_kwargs)
    else:
        plugin.obj = attr

    return plugin