serialization and versioning

[Neal Becker]

Etienne Robillard wrote:

> On Fri, 12 Oct 2012 06:42:03 -0400
> Neal Becker <ndbecker2 at gmail.com> wrote:
> 
>> I wonder if there is a recommended approach to handle this issue.
>> 
>> Suppose objects of a class C are serialized using python standard pickling.
>> Later, suppose class C is changed, perhaps by adding a data member and a new
>> constructor argument.
>> 
>> It would see the pickling protocol does not directly provide for this - but
>> is there a recommended method?
>> 
>> I could imagine that a class could include a class __version__ property that
>> might be useful - although I would further expect that it would not have been
>> defined in the original version of class C (but only as an afterthought when
>> it became necessary).
>> 
>> --
>> http://mail.python.org/mailman/listinfo/python-list
> 
> i guess a easy answer is to say to try python 3.3 but how would this translate
> in python (2) code ?

So are you saying python 3.3 has such a feature?  Where is it described?