Hydra is an open-source Python framework that simplifies the development of research and other complex applications. The key feature is the ability to dynamically create a hierarchical configuration by composition and override it through config files and the command line. The name Hydra comes from its ability to run multiple similar jobs - much like a Hydra with multiple heads.
- Hierarchical configuration composable from multiple sources
- Configuration can be specified or overridden from the command line
- Dynamic command line tab completion
- Run your application locally or launch it to run remotely
- Run multiple jobs with different arguments with a single command
Hydra supports Linux, Mac and Windows.
|Version||Docs||Release notes||Python Version|
|►||1.0 (Stable)||1.0 Docs||Release notes||3.6+|
|0.11||Switch to 0.11 Docs||Release notes||2.7, 3.5+|
This guide will show you some of the most important features of Hydra. Read the tutorial to gain a deeper understanding.
You can learn more about OmegaConf here later.
config.yaml is loaded automatically when you run your application
You can override values in the loaded config from the command line:
You may want to alternate between two different databases. To support this create a
config group named db,
and place one config file for each alternative inside:
The directory structure of our application now looks like:
Here is the new config:
defaults is a special directive telling Hydra to use db/mysql.yaml when composing the configuration object.
The resulting cfg object is a composition of configs from defaults with configs specified in your
You can now choose which database configuration to use and override values from the command line:
You can have as many config groups as you need.
You can run your function multiple times with different configuration easily with the
There is a whole lot more to Hydra. Read the tutorial to learn more.
Ask questions in the chat or StackOverflow (Use the tag #fb-hydra):
Follow Hydra on Twitter and Facebook:
If you use Hydra in your research please use the following BibTeX entry: