[Python-checkins] python/nondist/sandbox/datetime obj_delta.c,1.9,1.10

[Tim Peters]

[Guido]
> Try defining __reduce__.

OK ... but no joy:

        # XXX Pickling fails in the C implementation.
        # XXX timedelta has a __reduce__ method, which returns, e.g.,
        # XXX
        # XXX    (<type 'timedelta'>, (), (1, 0, 0))
        # XXX
        # XXX but pickle then complains
        # XXX
        # XXX     PicklingError: Can't pickle <type 'timedelta'>:
        # XXX     it's not found as __builtin__.timedelta

In one way that's not a mystery:

>>> timedelta.__module__
'__builtin__'
>>> timedelta.__name__
'timedelta'
>>>

OK, if I change the name of the type to "_datetime.timedelta", pickling
completes, but on unpicking a new error pops up:

UnpicklingError: <type '_datetime.timedelta'> is not safe for
                 unpickling

Arghghghgh ... OK, if I also give the type dict a __safe_for_unpickling__
attr, I guess it works.