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Version: 1.2

Specifying a config file

Β Example (Click Here)

It can get tedious to type all those command line arguments. You can solve it by creating a configuration file next to Hydra configuration files are yaml files and should have the .yaml file extension.

driver: mysql
user: omry
password: secret

Specify the config name by passing a config_name parameter to the @hydra.main() decorator. Note that you should omit the .yaml extension. Hydra also needs to know where to find your config. Specify the directory containing it relative to the application by passing config_path:
from omegaconf import DictConfig, OmegaConf
import hydra

@hydra.main(version_base=None, config_path=".", config_name="config")
def my_app(cfg):

if __name__ == "__main__":

config.yaml is loaded automatically when you run your application.

$ python
driver: mysql
user: omry
password: secret

You can override values in the loaded config from the command line.
Note the lack of the + prefix.

$ python db.user=root db.password=1234
driver: mysql
user: root
password: 1234

Use ++ to override a config value if it's already in the config, or add it otherwise. e.g:

# Override an existing item
$ python ++db.password=1234

# Add a new item
$ python ++db.timeout=5

You can enable tab completion for your Hydra applications.