René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Cannot unpickle polar plot","articleBody":"I create the polar plot example from http://matplotlib.org/examples/pie_and_polar_charts/polar_scatter_demo.html\n\nThen\n\n```\nfig = plt.gcf()\npf = pickle.dumps(fig)\nf2 = pickle.loads(pf)\n```\n\nthrows the following exception:\n\n```\n/home/joerg/applications/anaconda3/lib/python3.4/site-packages/matplotlib/transforms.py in __setstate__(self, data_dict)\n    116         self.__dict__ = data_dict\n    117         # turn the normal dictionary back into a WeakValueDictionary\n--\u003e 118         self._parents = WeakValueDictionary(self._parents)\n    119 \n    120     def __copy__(self, *args):\n\nAttributeError: 'PolarAffine' object has no attribute '_parents'\n```\n\nNote that this is separate from issue #3483 in that `plt.ioff()` before unpickling does not work.\n","author":{"url":"https://github.com/joergdietrich","@type":"Person","name":"joergdietrich"},"datePublished":"2015-02-06T09:06:30.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/4068/matplotlib/issues/4068"}