pickle's backward compatibility

[exarkun at twistedmatrix.com]

On 03:17 pm, pengyu.ut at gmail.com wrote:
>Hi,
>
>If I define my own class and use pickle to serialize the objects in
>this class, will the serialized object be successfully read in later
>version of python.
>
>What if I serialize (using pickle) an object of a class defined in
>python library, will it be successfully read in later version of
>python?

Sometimes.  Sometimes not.  Python doesn't really offer any guarantees 
regarding this.

Jean-Paul