[Python-Dev] Unpickling py2 str as py3 bytes (and vice versa) - implementation (issue #6784)

[Merlijn van Deen]

On 13 March 2012 22:13, Guido van Rossum <guido at python.org> wrote:
> Well, since trying to migrate data between versions using pickle is
> the "wrong" thing anyway, I think the status quo is just fine.
> Developers doing the "right" thing don't use pickle for this purpose.

I'm confused by this. "The pickle serialization format is guaranteed
to be backwards compatible across Python releases" [1], which - at
least to me - suggests it's fine to use pickle for long-term storage,
and that reading this data in new Python versions is not a "bad"
thing to do. Am I missing something here?

[1] http://docs.python.org/library/pickle.html#the-pickle-protocol