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I am working on a project where we have a large number of objects being serialized and stored to disk using pickle/cPickle.
As the life of the project progresses (after release to customers in the field) it is likely that future features/fixes will require us to change the signature of some of our persisted objects. This could be the addition of fields, removing of fields, or even just changing the invariants on a piece of data.
Is there a standard way to mark an object that will be pickled as having a certain version (like serialVersionUID in Java)? Basically, if I am restoring an instance of Foo version 234 but the current code is 236 I want to receive some notification on unpickle. Should I just go ahead and roll out my own solution (could be a PITA).
Thanks
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Save this question. Show activity on this post. When I use pickle, it works fine and I can dump any load.
Check pickle Version Windows To check which version of pickle is installed, use pip show pickle or pip3 show pickle in your Windows CMD, command line, or PowerShell.
Pickling (and unpickling) is alternatively known as “serialization”, “marshalling,” 1 or “flattening”; however, to avoid confusion, the terms used here are “pickling” and “unpickling”.
As we said earlier, the load() method can be used to unpickle the pickled Python object. You have to first open the pickled file using rb (read-binary) permission and pass the opened file to the load() method, as shown below. The load() method unpickles the data and returns the actual object.
The pickle format has no such proviso. Why don't you just make the "serial version number" part of the object's attributes, to be pickled right along with the rest? Then the "notification" can be trivially had by comparing actual and desired version -- don't see why it should be a PITA.
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