[Numpy-discussion] cPickle.loads and Numeric

[Peter Cock]

On Tue, Feb 25, 2014 at 4:41 PM, Alexander Belopolsky <ndarray at mac.com> wrote:
>
> On Tue, Feb 25, 2014 at 11:29 AM, Benjamin Root <ben.root at ou.edu> wrote:
>>
>> I seem to recall reading somewhere that pickles are not intended to be
>> long-term archives as there is no guarantee that a pickle made in one
>> version of python would work in another version, much less between different
>> versions of the same (or similar) packages.
>
> That's not true about Python core and stdlib.  Python developers strive to
> maintain backward compatibility and any instance of newer python failing to
> read older pickles would be considered a bug.  This is even true across 2.x
> / 3.x line.
>
> You mileage with 3rd party packages, especially 10+ years old ones may vary.

As an example of a 10+ year old project, Biopython has accidentally
broken some pickled objects from older versions of Biopython.

Accidental breakages aside, I personally would not use pickle for long
term storage. Domain specific data formats or something simple like
tabular data, or JSON seems safer.

Peter