Éric Araujo <merwok@netwok.org> added the comment: We’d have to be careful to distinguish attributes defined to be not assignable and CPython implementation details. In the absence of a definition in the doc, there is a chicken-and-egg problem, so I think a patch would have to be discussed on python-dev to get answers from the language designers. ---------- nosy: +eric.araujo versions: +Python 2.7, Python 3.1, Python 3.2 _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue7436> _______________________________________