Raymond Hettinger <raymond.hettinger@gmail.com> added the comment: It looks like the identity-implies-equality part of this has already been taken care of. The __hash__ invariant also appears to now have extensive coverage, some in the glossary and much more in the data model section of the reference. Cute puzzles like a __hash__ returning a random value can be left for stackoverflow. ---------- resolution: -> out of date stage: -> resolved status: open -> closed _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue23987> _______________________________________