What is Hangar?

Hangar is based off the belief that too much time is spent collecting, managing, and creating home-brewed version control systems for data. At it’s core Hangar is designed to solve many of the same problems faced by traditional code version control system (ie. Git), just adapted for numerical data:

• Time travel through the historical evolution of a dataset.

• Zero-cost Branching to enable exploratory analysis and collaboration

• Cheap Merging to build datasets over time (with multiple collaborators)

• Completely abstracted organization and management of data files on disk

• Ability to only retrieve a small portion of the data (as needed) while still maintaining complete historical record

• Ability to push and pull changes directly to collaborators or a central server (ie a truly distributed version control system)

The ability of version control systems to perform these tasks for codebases is largely taken for granted by almost every developer today; However, we are in-fact standing on the shoulders of giants, with decades of engineering which has resulted in these phenomenally useful tools. Now that a new era of “Data-Defined software” is taking hold, we find there is a strong need for analogous version control systems which are designed to handle numerical data at large scale… Welcome to Hangar!

The Hangar Workflow:

   Checkout Branch
          |
          ▼
 Create/Access Data
          |
          ▼
Add/Remove/Update Samples
          |
          ▼
       Commit

Log Style Output:

*   5254ec (master) : merge commit combining training updates and new validation samples
|\
| * 650361 (add-validation-data) : Add validation labels and image data in isolated branch
* | 5f15b4 : Add some metadata for later reference and add new training samples received after initial import
|/
*   baddba : Initial commit adding training images and labels

Learn more about what Hangar is all about at https://hangar-py.readthedocs.io/

Installation

Hangar is in early alpha development release!

pip install hangar

Documentation

https://hangar-py.readthedocs.io/

Development

To run the all tests run:

tox

Note, to combine the coverage data from all the tox environments run:

set PYTEST_ADDOPTS=--cov-append
tox

PYTEST_ADDOPTS=--cov-append tox