[Zope] array module and pickleing ques

[Charlie Reiman]

Testing it from the python interpreter, it appears you are correct.
array.array is not pickleable. As a wild guess, array is probably a C class
and they just neglected to add that support. Since you don't say why your
values must be two bytes, I can't offer any real work arounds.

But as a guess, you might be able to work something with array.array's
to/fromstring stuff, and keep the array.array in a volatile attribute.

> -----Original Message-----
> From: zope-admin@zope.org [mailto:zope-admin@zope.org]On Behalf Of Aseem
> Mohanty
> Sent: Tuesday, July 09, 2002 10:55 PM
> Cc: zope@zope.org
> Subject: Re: [Zope] array module and pickleing ques
>
>
> some more info: the error:
>
> Error Type: UnpickleableError
> Error Value: Cannot pickle objects
>
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> Traceback (innermost last):
>  File F:\KANDIN~1\lib\python\ZPublisher\Publish.py , line 150, in
> publish_module
>  File F:\KANDIN~1\lib\python\ZPublisher\Publish.py , line 114, in publish
>  File F:\KANDIN~1\lib\python\Zope\__init__.py , line 158, in
> zpublisher_exception_hook
>  File F:\KANDIN~1\lib\python\ZPublisher\Publish.py , line 102, in publish
>  File F:\KANDIN~1\lib\python\Zope\__init__.py , line 172, in commit
>  File f:\kandinsky\lib\python\Products\TransactionAgents\__init__.py ,
> line 54, in new_commit
>  File F:\KANDIN~1\lib\python\ZODB\Transaction.py , line 233, in commit
>  File F:\KANDIN~1\lib\python\ZODB\Connection.py , line 345, in commit
>    (Info: (('Products.RC2.RC2', 'RC2'), '\x00\x00\x00\x00\x00\x00h\xe1',
> ''))
> UnpickleableError: (see above)
>
>
> I also tried the following in the python console:
>
> Python 2.1.2 (#31, Jan 15 2002, 17:28:11) [MSC 32 bit (Intel)] on win32
> Type "copyright", "credits" or "license" for more information.
>  >>> import pickle, array, os
>  >>> f= open('test','w')
>  >>> x = array.array('H')
>  >>> pickle.dump(x,f)
> Traceback (most recent call last):
>  File "<stdin>", line 1, in ?
>  File "F:\KANDIN~1\bin\lib\pickle.py" , line 939, in dump
>    Pickler(file, bin).dump(object)
>  File "F:\KANDIN~1\bin\lib\pickle.py" , line 109, in dump
>    self.save(object)
>  File "F:\KANDIN~1\bin\lib\pickle.py" , line 171, in save
>    raise PicklingError, \
> pickle.PicklingError: can't pickle 'array' object: array('H')
>  >>>
>
> The problem is that I NEED that array sizes to be 1 or 2 bytes  and I
> dont know how to get around this problem without arrays.
>
> Any help would be greatly appreciated.
>
> TIA
> AM
>
> Aseem Mohanty wrote:
>
> > why does a call to array.array() cause an unpickleable error??
> >
> > the pickle docs on the python site dont mention anything about arrays,
> > nor do the array docs mention about pickling.
> >
> > i have a feeling that it might be because of the fact that arrays are
> > dynamic data structures and thus the pickler doesnt really know about
> > its limits (of course I could be totally and miserably  wrong) i
> > couldnt find anything in the docs to support my 'feeling' and the
> > source is kind of above my current level of expertise in python
> >
> > any help would be appreciated or i am doomed to a major rewrite....
> >
> > the source in my product that causes the error :
> >
> > self.K=array.array('H')
> > self.L=array.array('B')
> > self.R=array.array('H')
> >
> > TIA
> > AM
> >
>
> --
> ==================================================================
>  Aseem Mohanty
>  Neurobehavioral Systems Inc, 828 San Pablo Ave, Albany, CA 94706
>  (R) 510 7696011 (M) 510 3014871 (O) 510 5279231
> ============================================================
> ======
>  "I saw `cout' being shifted "Hello world" times to the left and
>   stopped right there!!"                        -- Steve Gonedes
> ==================================================================
>
>
>
>
>
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