Add encoding rule for Namespace

[tristandeleu]

• Add an encoding rule for Namespace type, in order to directly call encode over the arguments parsed by argparse/simple-parsing.

[tristandeleu]

Personally I'd be using it for logging the configuration in Weights & Biases. Usually when I'm using argparse, wandb directly converts Namespace into a dictionary (they most likely simply do vars(args)) they can send to the server.

When I'm using simple-parsing with wandb, the dataclasses are serialized as a raw string; for example

"metalearner": {
    "desc": null,
    "value": "MAMLArguments(alpha=0.01, num_steps=5)"
}

Even though this retains all the information about my configuration (I can simply do eval(config['metalearner']) to get the dataclass back), it makes searching on the wandb side impossible (e.g. I can't search by metalearner.num_steps).

I was looking at a way to serialize the whole args in such a way that it would be wandb-friendly, and I came across the amazing encode function, which does exactly that (converts a datastructure, including dataclasses, into a dictionary). This rule is just for convenience to encode the whole Namespace at once, without having to encode(vars(args)). Concretely, here is what logging the config looks like:

wandb.config.update(encode(args))

(I originally intended to have the rule defined in my project, but I figured this might be of general interest)

[lebrice]

Interesting!

Are you using Serializable (from simple_parsing.helpers) as a base class for your Config? (I suspect you are, but if not, take a look at this example.)

Bonus: Off-topic, but I'd encourage you to check out the HyperParameters class, it's the kind of thing I hope you might like. The idea is to let people write the priors for their hyper-parameters directly in code. It has nice a integration with orion and is easy to log with wandb (as you did above). Providing a tighter integration with wandb is something I think could be interesting.

Let me know what you think :)