On Fri, Oct 12, 2018 at 9:16 AM Steven D'Aprano <st...@pearwood.info> wrote: > > On Fri, Oct 12, 2018 at 02:45:30AM +1100, Chris Angelico wrote: > > On Fri, Oct 12, 2018 at 2:41 AM Chris Barker - NOAA Federal via > > Python-ideas <python-ideas@python.org> wrote: > > > > > > > This violates the Liskov Substitution Principle. > > > > > > If we REALLY had a time machine, then dict would subclass frozendict, > > > and we’d be all set. > > > > Thanks to virtual subclassing, we can still do this. The question is, > > should we? > > > > Intuition tells me that a frozen dictionary is a form of dictionary > > that adds restrictions, not that a dictionary is a frozen dictionary > > that you left out to thaw. > > No offence Chris, but that's why we shouldn't program by intuition :-) > > > But as we see from [frozen]set, it's > > probably best to treat them as completely independent classes, both > > implementing the basic Mapping interface. > > Indeed. >
Which was my point. They probably should NOT be in a direct hierarchy, partly because people's intuition WILL lead them to a dangerous expectation. ChrisA _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
