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From: Ian Kelly <ian.g.kelly@gmail.com>
Newsgroups: comp.lang.python
Subject: Re: A pickle problem!
Date: Fri, 22 Apr 2016 10:27:34 -0600
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On Thu, Apr 21, 2016 at 7:52 PM, Paulo da Silva
<p_s_d_a_s_i_l_v_a_ns@netcabo.pt> wrote:
> =C3=80s 22:43 de 21-04-2016, Paulo da Silva escreveu:
>> Hi.
>>
>> Why in this code fragment self.__name is not kept between pickle
>> dumps/loads? How to fix it?
>>
>> Thanks.
>>
>> import pickle
>> import pandas as pd
>> import numpy as np
>>
>> class C(pd.DataFrame):
>>       def __init__(self,name,*a,**b):
>>               super(C,self).__init__(*a,**b)
>>               self.__name=3Dname
>>
>>       def GetName(self):
>>               return self.__name
>>
> # Adding this works but looks tricky!
>
>         def __getstate__(self):
>                 dfstate=3Dsuper(C,self).__getstate__()
>                 cstate=3D(dfstate,self.__name)
>                 return cstate
>
>         def __setstate__(self,cstate):
>                 super(C,self).__setstate__(cstate[0])
>                 self.__name=3Dcstate[1]

Probably this is necessary because the DataFrame class is already
customizing its pickle behavior without taking into account the
possibility of added attributes by subclasses. I think that your
solution of wrapping the state of the superclass looks fine.