On Sun, Nov 21, 2010 at 1:29 AM, Michael Foord <fuzzy...@voidspace.org.uk> wrote: > Can you give an example of code in a metaclass that may be executed by > getattr_static? It's not that I don't believe you I just can't think of an > example. Looking up the class and the mro are the only two examples I can > think of (klass.__mro__ and instance.__class__ - and they are noted in the > docs?) but aren't metaclass specific.
The description heavily implies that arbitrary Python code won't be executed by calling getattr_static, and that isn't necessarily true. It's almost certain to be true in the case when the metaclass is type, but can't be guaranteed otherwise. The retrieval of __class__ is a normal lookup on the object, so it can trigger all of the things getattr_static is trying to avoid (unavoidable if you want to support proxy classes at all), and the lookup of __mro__ invokes all of those things on the metaclass. I'll see if I'm still of the same opinion after I sleep on it, but my first impression of the docs was that they slightly oversold the strength of the "doesn't execute arbitrary code" aspect of the new function. The existing caveats were all relating to when getattr() and getattr_static() might give different answers, while the additional caveats I was suggesting related to cases where arbitrary code may still be executed. Cheers, Nick. -- Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
