enhancement request: make py3 read/write py2 pickle format

[Irmen de Jong]

On 10-6-2015 1:06, Chris Angelico wrote:
> On Wed, Jun 10, 2015 at 6:07 AM, Devin Jeanpierre
> <jeanpierreda at gmail.com> wrote:
>> There's a lot of subtle issues with pickle compatibility. e.g.
>> old-style vs new-style classes. It's kinda hard and it's better to
>> give up. I definitely agree it's better to use something else instead.
>> For example, we switched to using protocol buffers, which have much
>> better compatibility properties and are a bit more testable to boot
>> (since text format protobufs are always output in a canonical (sorted)
>> form.)
> 
> Or use JSON, if your data fits within that structure. It's easy to
> read and write, it's human-readable, and it's safe (no chance of
> arbitrary code execution). Forcing yourself to use a format that can
> basically be processed by ast.literal_eval() is a good discipline -
> means you don't accidentally save/load too much.
> 
> ChrisA
> 

I made a specialized serializer for this, which is more expressive than JSON. It outputs
python literal expressions that can be directly parsed by ast.literal_eval(). You can
find it on pypi (https://pypi.python.org/pypi/serpent).  It's the default serializer of
Pyro, and it includes a Java and .NET version as well as an added bonus.


Irmen