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|
|►||0.11 (Stable)||0.11 Doc||Release notes||2.7, 3.5+|
|1.0 (Release candidate)||Switch to 1.0 Docs||Release notes||3.6+|
Quick start guide
This guide will show you some of the most important features of Hydra. Read the tutorial to gain a deeper understanding.
Install Hydra 0.11 with
pip install hydra-core --upgrade.
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
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 from the 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: