python - PicklingError: Can't pickle <class 'decimal.Decimal'>: it's not the same object as decimal.Decimal

Question

This is the error I got today at <a href"http://filmaster.com">filmaster.com:

PicklingError: Can't pickle <class
'decimal.Decimal'>: it's not the same
object as decimal.Decimal

What does that exactly mean? It does not seem to be making a lot of sense... It seems to be connected with django caching. You can see the whole traceback here:

Traceback (most recent call last):

 File
"/home/filmaster/django-trunk/django/core/handlers/base.py",
line 92, in get_response    response =
callback(request, *callback_args,
**callback_kwargs)

 File
"/home/filmaster/film20/film20/core/film_views.py",
line 193, in show_film   
workflow.set_data_for_authenticated_user()

 File
"/home/filmaster/film20/film20/core/film_views.py",
line 518, in
set_data_for_authenticated_user   
object_id = self.the_film.parent.id)

 File
"/home/filmaster/film20/film20/core/film_helper.py",
line 179, in get_others_ratings   
set_cache(CACHE_OTHERS_RATINGS,
str(object_id) + "_" + str(user_id),
userratings)

 File
"/home/filmaster/film20/film20/utils/cache_helper.py",
line 80, in set_cache    return
cache.set(CACHE_MIDDLEWARE_KEY_PREFIX
+ full_path, result, get_time(cache_string))


 File
"/home/filmaster/django-trunk/django/core/cache/backends/memcached.py",
line 37, in set   
self._cache.set(smart_str(key), value,
timeout or self.default_timeout)

 File
"/usr/lib/python2.5/site-packages/cmemcache.py",
line 128, in set    val, flags =
self._convert(val)

 File
"/usr/lib/python2.5/site-packages/cmemcache.py",
line 112, in _convert    val =
pickle.dumps(val, 2)

PicklingError: Can't pickle <class
'decimal.Decimal'>: it's not the same
object as decimal.Decimal

And the source code for Filmaster can be downloaded from here: bitbucket.org/filmaster/filmaster-test

Any help will be greatly appreciated.

Answer 1

I got this error when running in an jupyter notebook. I think the problem was that I was using %load_ext autoreload autoreload 2. Restarting my kernel and rerunning solved the problem.