[Python-ideas] Re: Pickle improvement: global qualnames for local classes

On Fri, Sep 4, 2020 at 7:19 PM haael haael@interia.pl wrote:

Yes, but that could also be said about ordinary global classes.

(Please don't top-post, it makes it very difficult to usefully quote multiple people.)

 if sys.args[1] == "a":
     class A:
        pass

     a = A()

     print(pickle.dumps(a))
 else:
     a = pickle.loads(input()) # no definition of class A in this run

...

Apologies if I'm misunderstanding your point here, but it feels like what you're proposing would only work if you pickled and unpickled the data in the *same* running instance of the program.

Of course you COULD do that, but generally, any run of the program will create equivalent classes with the same name. What you're proposing would have some sort of unique ID generated for every class, so how do you ensure that the correct class has the same ID?

If you're able to correctly match a class to its identifier, you could far better do this yourself - or alternatively, have them all be the SAME class with some sort of parameterization.

ChrisA