Using the config object

 

Your configuration object is an instance of OmegaConf's DictConfig.
Here are some of the basic features:

config.yaml

node:                         # Config is hierarchical
  loompa: 10                  # Simple value
  zippity: ${node.loompa}     # Value interpolation
  do: "oompa ${node.loompa}"  # String interpolation
  waldo: ???                  # Missing value, must be populated prior to access

my_app.py

@hydra.main(config_name="config")
def my_app(cfg: DictConfig):
    assert cfg.node.loompa == 10          # attribute style access
    assert cfg["node"]["loompa"] == 10    # dictionary style access

    assert cfg.node.zippity == 10         # Value interpolation
    assert isinstance(cfg.node.zippity, int)  # Value interpolation type
    assert cfg.node.do == "oompa 10"      # string interpolation

    cfg.node.waldo                        # raises an exception

Outputs:

$ python my_app.py 
Missing mandatory value: waldo
        full_key: waldo
        reference_type=Optional[Dict[Any, Any]]
        object_type=dict

You can learn more about OmegaConf here.