On Tue, 30 Aug 2016 17:35:35 +0000 Brett Cannon <br...@python.org> wrote: > > > > Perhaps a list would work indeed. Realistically, if there are at most > > 2-3 users of the field at any given time (and most probably only one or > > zero), a simple type check (by pointer equality) on each list item may > > be sufficient. > > > > Let's see what Maciej says, but we could standardize on switching the field > to a list when a conflict of usage is detected so the common case in the > frame eval function is checking for your own type, and if that fails then > doing a PyList_CheckExact() and look for your object, otherwise make a list > and move over to that for everyone to use. A little bit more code, but it's > simple code and takes care of conflicts only when it calls for it.
That's a bit obscure and confusing, though (I *think* the weakref module uses a similar kludge in some place). If you want to iterate on it you have to write some bizarre macro to share the loop body between the two different code-paths (list / non-list), or some equally tedious function-pointer-based code. Why not make it always a list? List objects are reasonably cheap in memory and access time... (unlike dicts) Regards Antoine. _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
