Don't fail if cPickle doesn't exist.

from django.utils import translation

from django.utils.cache import (patch_vary_headers, get_cache_key,

    learn_cache_key, patch_cache_control, patch_response_headers)

from django.utils.six.moves import cPickle as pickle

from django.utils.encoding import force_text

from django.views.decorators.cache import cache_page

try:    # Use the same idiom as in cache backends

    from django.utils.six.moves import cPickle as pickle

except ImportError:

    import pickle

from .models import Poll, expensive_calculation