The documentation states: """Objects such as modules and instances have an updateable __dict__ attribute; however, other objects may have write restrictions on their __dict__ attributes (for example, classes use a dictproxy to prevent direct dictionary updates)."""
However, it's not clear from that *why* direct dictionary updates are undesirable. This not only prevents you from getting a reference to the real class dict (which is the apparent goal), but is also the fundamental reason why you can't use a metaclass to put, say, an OrderedDict in its place - because the type constructor has to copy the dict that was used in class preparation into a new dict rather than using the one that was actually returned by __prepare__. [Also, the name of the type used for this is mappingproxy, not dictproxy] _______________________________________________ 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
