pickling extension class

[harold fellermann]

On 18.01.2005, at 20:31, Alex Martelli wrote:

> harold fellermann <harold.fellermann at upf.edu> wrote:
>
>>    File "/sw/lib/python2.4/pickle.py", line 760, in save_global
>>      raise PicklingError(
>> pickle.PicklingError: Can't pickle <type 'hyper.PeriodicGrid'>: it's
>> not found as hyper.PeriodicGrid
>>>>> dir(hyper)
>> ['Dir', 'Neighbors', 'PeriodicGrid', 'PeriodicPos', '__doc__',
>> '__file__', '__name__', 'refcount']
>>>>> hyper.PeriodicGrid
>> <type 'hyper.PeriodicGrid'>
>>
>> So pickle complains about the class PeriodicGrid not being found in 
>> the
>> module hyper, but a dir()
>> proves that python can find it. Has anyone an idea what's going wrong
>> here?
>
> These symptomps are pretty weird -- let's try to pin things down a bit
> more.  The relevant few lines of pickle.py are:
>
>         try:
>             __import__(module)
>             mod = sys.modules[module]
>             klass = getattr(mod, name)
>         except (ImportError, KeyError, AttributeError):
>             raise PicklingError(
>
> so, could you please edit your pickle.py to provide VASTLY more info,

[...]

> and let us know exactly what his modified pickle.py outputs...?


Here it goes...:
  OOPS, error (exceptions.ImportError): No module named hyper
Traceback (most recent call last):
   File "pickle_test.py", line 5, in ?
     pickle.dump(g,file("test","w"))
   File "/Volumes/space/Users/harold/uni/pace/ono/pickle.py", line 1387, 
in dump
     Pickler(file, protocol, bin).dump(obj)
   File "/Volumes/space/Users/harold/uni/pace/ono/pickle.py", line 231, 
in dump
     self.save(obj)
   File "/Volumes/space/Users/harold/uni/pace/ono/pickle.py", line 338, 
in save
     self.save_reduce(obj=obj, *rv)
   File "/Volumes/space/Users/harold/uni/pace/ono/pickle.py", line 414, 
in save_reduce
     save(func)
   File "/Volumes/space/Users/harold/uni/pace/ono/pickle.py", line 293, 
in save
     f(self, obj) # Call unbound method with explicit self
   File "/Volumes/space/Users/harold/uni/pace/ono/pickle.py", line 765, 
in save_global
     raise PicklingError(
pickle.PicklingError: Can't pickle <type 'hyper.PeriodicGrid'>: it's 
not found as hyper.PeriodicGrid


I have noticed that the error does not occur, when the imported module 
('hyper') is in the same directory as the script that pickles. When it 
is imported from a subpackage (like in the code
I sent you) it goes wrong.

- harold -

--
Reality is for people who lack imagination.