> Aha, that's useful to know. So it's a no-no to subclass *any* builtin?
I don't think it's a no-no, I just think it comes with a few problems that are solved if you subclass the classes that are *meant* to be subclassed, like UserDict, UserList, or UserString. > I checked collections.UserDict and it indeed looks promising. Caveat: it;s > Python 3 only (not sure what versionit was introduced). It's in both Python 2 and 3, but they're not in the same module. That's why I used the following construct to import it. In both cases, UserDict is imported correctly and the module where it came from does not matter. try: from collections import UserDict except ImportError: from UserDict import UserDict Here are the docs: - Python 2: https://docs.python.org/2/library/userdict.html - Python 3: https://docs.python.org/3/library/collections.html#collections.UserDict Regards, Alex _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor