I can “pickle local objects” if I use a derived class?

Question

The pickle reference states that the set of objects which can be pickled is rather limited. Indeed, I have a function which returns a dinamically-generated clas

Answer 1

I disagree, you can pickle both. You just need to use a better serializer, like dill. dill (by default) pickles classes by saving the class definition instead of pickling by reference, so it won't fail your first case. You can even use dill to get the source code, if you like.

>>> import dill as pickle
>>> def f():
...   class A: pass
...   return A
... 
>>> localA = f()
>>> la = localA()
>>> 
>>> _la = pickle.dumps(la)
>>> la_ = pickle.loads(_la)
>>>    
>>> class DerivedA(localA): pass
... 
>>> da = DerivedA()
>>> _da = pickle.dumps(da)
>>> da_ = pickle.loads(_da)
>>> 
>>> print(pickle.source.getsource(la_.__class__))
  class A: pass

>>>