enhancement request: make py3 read/write py2 pickle format

[random832 at fastmail.us]

On Wed, Jun 10, 2015, at 19:30, Gregory Ewing wrote:
> If whitelisting a type is the *only* thing you need to
> do to make it serialisable, I think that comes close
> enough to the stated goal of being able to "serialise
> all [potentially serialisable] language objects".

IMO the serialization framework should handle this by providing your own
way to look them up (almost but not entirely unlike providing your own
globals table to eval) rather than by having a whitelist.