> If Py_None corresponds to None in Python syntax (sorry I'm not familiar > with Python internals yet; glad you are commenting, since you are), then > it is a fixed constant and could be left global, probably.
If None remains global, then type(None) also remains global, and type(None),__bases__[0]. Then type(None).__bases__[0].__subclasses__() will yield "interesting" results. This is essentially the status quo. > But if we > want a separate None for each interpreter, or if we just use Py_None as > an example global variable to use to answer the question then here goes There are a number of problems with that approach. The biggest one is that it is theoretical. Of course I'm aware of thread-local variables, and the abstract possibility of collecting all global variables in a single data structure (in fact, there is already an interpreter structure and per-interpreter state in Python). I wasn't claiming that it was impossible to solve that problem - just that it is not simple. If you want to find out what all the problems are, please try implementing it for real. Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
