Simple command line application

This is a simple Hydra application that prints your configuration. The my_app function is a place holder for your code. We will slowly evolve this example to show-case more Hydra features.

The examples in this tutorial are available here.

Python file: my_app.py

import hydra

@hydra.main()
def my_app(cfg):
    print(OmegaConf.to_yaml(cfg))

if __name__ == "__main__":
    my_app()

The cfg is an OmegaConf object that holds the configuration for your function. You don't need a deep understanding of OmegaConf for this tutorial.

We can pass arbitrary command line arguments from which Hydra creates a hierarchical configuration object:

$ python my_app.py db.driver=mysql db.user=omry db.pass=secret
db:
  driver: mysql
  pass: secret
  user: omry