Question

The python docs say:
pickle can save and restore class instances transparently, however the class definition must be importable and live in the same module as when the object was stored.
Could I put a pickler/unpickler in the module where the class was stored?
Or do I have to put the class in the module? And how?
I’m trying to pickle/unpickle a object from a class in a external module.

Answer 1

You can pickle any python class instance, as long as the pickle module can import it again when you load the pickle.

It doesn’t matter where in your python code you use load() or dump(), it only matters if the data that you are going to pickle can be retrieved again later on, by importing them from the same location.

So, if you have a module foo.bar with a class Spam in it, then as long as you can do from foo.bar import Spam you can pickle instances of that class, because pickle can later on load that class again from the same module.