[Python-Dev] doctest and pickle
Ethan Furman
ethan at stoneleaf.us
Sat Jun 8 09:03:14 CEST 2013
On 06/07/2013 11:45 PM, Steven D'Aprano wrote:
> On 08/06/13 15:18, Stephen J. Turnbull wrote:
>> Ethan Furman writes:
>>
>> > Enumerations can be pickled and unpickled::
>> >
>> > >>> from enum import Enum
>> > >>> class Fruit(Enum):
>> > ... tomato = 1
>> > ... banana = 2
>> > ... cherry = 3
>> > ...
>> > >>> from pickle import dumps, loads
>> > >>> Fruit.tomato is loads(dumps(Fruit.tomato))
>> > True
>> > [...]
>> > Still, it would be nice if this could work.
>>
>> Well, you could cheat and reverse the test. ;-)
>>
>> I assume the problem is that loads proceeds to recreate the Fruit
>> enum, rather than checking if there already is one?
>
>
> I don't believe so. I understand that the problem is that pickle cannot find the Fruit enum in the __main__ module.
>
> Untested, but adding this before the call to dumps might work:
>
> import __main__
> __main__.Fruit = Fruit
>
>
> although that's the sort of thing that makes me think it's time to turn this into a unittest rather than a doctest.
Indeed, and it is already in several different ways. But it would be nice to have a pickle example in the docs that
worked with doctest.
I ended up doing what Barry did:
>>> from test.test_enum import Fruit
>>> from pickle import dumps, loads
>>> Fruit.tomato is loads(dumps(Fruit.tomato))
True
--
~Ethan~
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