How to pickle yourself?

python pickle
user317033 picture user317033 · Apr 25, 2010 · Viewed 19.5k times · Source

I want my class to implement Save and Load functions which simply do a pickle of the class. But apparently you cannot use 'self' in the fashion below. How can you do this?

self = cPickle.load(f)

cPickle.dump(self,f,2)

Answer

user317033 picture user317033 · May 16, 2010

This is what I ended up doing. Updating the __dict__ means we keep any new member variables I add to the class and just update the ones that were there when the object was last pickle'd. It seems the simplest while maintaining the saving and loading code inside the class itself so calling code just does an object.save().

def load(self):
    f = open(self.filename, 'rb')
    tmp_dict = cPickle.load(f)
    f.close()          

    self.__dict__.update(tmp_dict) 


def save(self):
    f = open(self.filename, 'wb')
    cPickle.dump(self.__dict__, f, 2)
    f.close()

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