OmegaConf is nice and has more features than YACS.

Merging (from the help)

conf = OmegaConf.merge(base_cfg, model_cfg, optimizer_cfg, dataset_cfg)

Bits I can’ find explicitly documented anywhere:

OmegaConf.merge() takes the first argument as “base”, and its keys should be a superset of keys in the next one or it errors out (from omegaconf.errors import ConfigKeyError).

It casts arguments automatically, if first argument’s key is a Path and the second is a str the merged one will be a Path(str_from_second_argument), beautiful!