I'm able to do this in my ndarrary subclass using __reduce__ and __setstate__:
https://bitbucket.org/yt_analysis/yt/src/yt/yt/units/yt_array.py#yt_array.py-1250 Here it's being used to save the unit information into the pickle for a unit-aware ndarray subclass. On Wed, Dec 14, 2016 at 1:45 PM, Stuart Reynolds <stu...@stuartreynolds.net> wrote: > I'm trying to subclass an NDArray as shown here: > https://docs.scipy.org/doc/numpy/user/basics.subclassing.html > > My problem is that when I save the new class' state with pickle, the new > attributes are lost. I don't seem to be able to override __getstate__ or > __setstate__ to achieve this? > > Is it possible to allow new state to serialized when overriding an NDArray? > > In my example below, __setstate__ gets called by pickle but not > __getstate__. > In the final line, a RealisticInfoArray has been deserialized, but it has > no .info attribute. > > ---- > > import cPickle as pickle > import numpy as np > > class RealisticInfoArray(np.ndarray): > def __new__(cls, arr, info): > obj = np.asarray(arr).view(cls) > obj.info = info > return obj > > def __array_finalize__(self, obj): > if obj is None: return > self.info = getattr(obj,"info",None) > > def __setstate__(self, *args): > print "SET" > return np.ndarray.__setstate__(self,*args) > > def __getstate__(self): > print "GET" > assert False, "EXPLODE" > return np.ndarray.__getstate__(self) > > arr = np.zeros((2,3), int) > arr = RealisticInfoArray(arr, "blarg") > print arr.info > arr2 = pickle.loads(pickle.dumps(arr)) > print arr2.info # no .info attribute! > > > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > https://mail.scipy.org/mailman/listinfo/numpy-discussion > >
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