Raymond Hettinger <rhettin...@users.sourceforge.net> added the comment:
> To solve the problem, KeysView and ItemsView need > to override _from_iterable to return a set instead > of a new view. Thanks for the good analysis and suggested fix. I believe both are correct and they match the behavior of real dictionaries. def _from_iterable(self, it): return set(it) Proposed tests to match real dicts: x = MySimpleMapping() # from stuzback's example x['red'] = 5 y = x.keys() assert isinstance(y, collections.Set) assert not isinstance(y, collections.MutableSet) z = x.keys() | {'orange'} assert type(z) is set ---------- priority: normal -> high _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue9214> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com