At 08:57 AM 6/1/03 -0400, Guido van Rossum wrote:

(I'd like to review this more carefully when I have more time, but one thing jumped out at me:)

[Phillip Eby]

...

It would be a good idea to add some information about "data" and "non-data" descriptors, and the differences of how their attribute lookup is processed. I recently posted here about the "attribute lookup process" or something to that effect, which covered this. Understanding data vs. non-data descriptors is important if you want to do pretty much anything with descriptors beyond what property() does.

Note that I recently changed the treatment of data descriptors by super() in 2.3. typeobject.c rev 2.227/2.228:

And an important change it is. If you define methods on metaclasses that might also be defined by their instances (i.e. the classes) on behalf of *their* instances, the only way to get this to work right is to use data descriptors for the metaclass level methods. Which then means super() breaks, so for 2.2 I have a custom 'super()' to work with data descriptors. I rather wish you'd considered it a bugfix rather than a new feature. :)