[Python-3000] Simplifying pickle for Py3k (original) (raw)

Alexandre Vassalotti alexandre at peadrop.com
Thu Oct 4 08:49:16 CEST 2007

On 10/3/07, Neil Schemenauer <nas at arctrix.com> wrote:

I guess the library overhaul hasn't really started it but it would be nice if the pickle module could get some work. Today I'm trying to efficiently store a class using pickle

Could you elaborate on what you are trying to do?

and the documentation is making my head hurt. I don't think the documentation itself is the problem, just the fact that the rules are so complicated.

I guess there are several different solutions: * Remove backwards compatible stuff from the code and the documentation. The downside is that old pickles could not be loaded. Perhaps that's not a huge issue since the removal of old-style classes might already break old pickles.

This would not simplify the pickle module by much. So, I don't think this would justify breaking backward-compatibility.

As far as I know, the removal of the old-style classes does not break old pickle streams, since the code of classes is not pickled but referenced.

* Remove the backwards compatible stuff from the documentation only. The would help people using the language but would still be a long term maintenance issue.

The documentation for the pickle module is completely outdated and confusing. In fact, some sections are outright wrong about how the current module works. If I get some free time (which is unlikely, right now), I will update the documentation.

* Leave the old code in but generate warnings when old pickle mechanisms are used. Eventually the old stuff could be removed from the code.

Could point out specific examples of the "old code" that you are referring to?

* Provide an "oldpickle" module the supports pre-3k pickles.

As I said, old pickle streams should work fine with Py3k. So, adding yet another pickle module is unnecessary.

-- Alexandre

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