I'm approaching "how to make cache failures not crash on you every time you import anything". So in short, file like ll_os.py looks right now: if cache.defined('XXX'): TYPE = cache.inttype(...) register_external(...) Idea is that if any of the functions involved in creation of external (cache functions...), show a warning and than create a register_external stub which will explode if referenced (by ie a specific extregistry entry). The question is how it should look like than. My idea is: class Os(registeringclass): def register_os_uname(...): ... def register_os_other(...): ... and so on. This will create huge indentation. Any other ideas? Cheers, fijal :.