kansha/pickle.py
#--
# Copyright (c) 2012-2014 Net-ng.
# All rights reserved.
#
# This software is licensed under the BSD License, as described in
# the file LICENSE.txt, which you should have received as part of
# this distribution.
#--
from __future__ import absolute_import
import pickle
from nagare import database
# if objgraph is installed, it renders a graph that can help finding why
# the object is pickled
try:
import objgraph
except ImportError:
objgraph = None
class UnpicklableMixin(object):
def __reduce__(self):
if objgraph:
database.session.expire_all()
objgraph.show_backrefs([self], max_depth=5)
raise pickle.PicklingError(
'This object is not picklable: {!r}'.format(self)
)