On 2014-10-26, Terry Reedy <tjre...@udel.edu> wrote: > On 10/26/2014 10:14 AM, Jon Ribbens wrote: >> Is there any better way to do this other than simply re-implementing >> these types from scratch, emulating all their methods and operations? >> (i.e. using UserList/UserDict). I was under the impression that that >> sort of thing was supposed to have gone since Python 2.2 or so. > > We considered dropping UserDict and UserList for 3.0 but kept them in > collections for cases in which subclassing does not work.
It seems on further investigation to be hard/impossible to subclass Python classes from C extensions. I've gone with subclassing dict, and reimplementing most of its methods. It helps that I only need it to be read-only. It's a pity there's no protocol for 'dynamic' lists/dicts though. -- https://mail.python.org/mailman/listinfo/python-list