cannot pickle object returned by urllib2.urlopen()

[scsoce]

got a exception: "a class that defines __slots__ without defining
__getstate__ cannot be pickled "
why?
and is there any other dump method but for pickle to store the kind of
object ?

[Steven D'Aprano]

Re: cannot pickle object returned by urllib2.urlopen ()

On Wed, 12 Nov 2008 11:00:26 +0800, scsoce wrote:

got a exception: "a class that defines __slots__ without defining
__getstate__ cannot be pickled "
why?
and is there any other dump method but for pickle to store the kind of
object ?

I can't answer either of your questions, but why are you trying to pickle
an open connection to a (possibly remote) URL? I can't imagine how that
could possibly work even in principle.



--
Steven

[greg]

Re: cannot pickle object returned by urllib2.urlopen ()

On Wed, 12 Nov 2008 11:00:26 +0800, scsoce wrote:

>

>>got a exception: "a class that defines __slots__ without defining
>>__getstate_ _ cannot be pickled "
>>why?

Because in the absence of any other information, the default
way of pickling an object is to save the contents of its
__dict__. But an object with __slots__ doesn't necessarily
have a __dict__, and even if it does, it doesn't include
the contents of the slots. So you need to tell pickle how to
deal with it by defining __getstate__ and __setstate__ methods.

--
Greg