ispicklable() --> bool, possible?

[Gerrit Holl]

Jp Calderone schreef op dinsdag 25 februari om 01:57:30 +0000:
>   I would use just this last portion
> 
> >     try:
> >         cPickle.dumps(obj)
> >     except (TypeError, cPickle.UnpickleableError):
> >         return False
> >     else:
> >         return True
> 
>   Did you discard this approach for performance reasons?

No, I discard it for another reason. I am calling picklable()
from __getstate__, because if it isn't picklable, I need to do
some operation on it. One of the attributes of my instance is
another instance of the same superclass. So if I call picklable(),
the function tries to pickle the object. When trying to pickle it,
the __getstate__ method calls picklable() on its attributes, and
one of the attributes is, again, another instance of the same superclass.
This way, I get an infinite loop.

In reality, I am using the pygame library. Each sprite contains an
attribute listing the groups it's a member of, and each group contains
an attribute listing the sprites living in the group. Additionaly,
some of my sprites (bullets) contain an attribute 'origin' which is
a reference to another sprite instance. I could of course check in
my __getstate__ whether an attribute is called '_Sprite__g', 'origin'
or something else, but that approach is very ugly and importable (I
will need to change it every time I change my internal API).

yours,
Gerrit.

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