Developer Guide

EinsteinPy is a community project. Hence, all contributions are more than welcome!

Reporting Bugs

Not only things break all the time, but also different people have different use cases for the project. If you find anything that doesn’t work as expected or have suggestions, please refer to the issue tracker on GitHub.


Documentation can always be improved and made easier to understand for newcomers. The docs are stored in text files under the docs/source directory, so if you think anything can be improved there please edit the files and proceed in the same way as with code writing.

The Python classes and methods also feature inline docs: if you detect any inconsistency or opportunity for improvement, you can edit those too.

Besides, the wiki is open for everybody to edit, so feel free to add new content.

To build the docs, you must first create a development environment (see below) and then in the docs/ directory run:

$ cd docs
$ make html

After this, the new docs will be inside build/html. You can open them by running an HTTP server:

$ cd build/html
$ python -m http.server
Serving HTTP on port 8000 ...

And point your browser to

Code writing

Code contributions are welcome! If you are looking for a place to start, help us fixing bugs in einsteinpy and check out the “easy” tag. Those should be easier to fix than the others and require less knowledge about the library.

If you are hesitant on what IDE or editor to use, just choose one that you find comfortable and stick to it while you are learning. People have strong opinions on which editor is better so I recommend you to ignore the crowd for the time being - again, choose one that you like :)

If you ask me for a recommendation, I would suggest PyCharm (complete IDE, free and gratis, RAM-hungry) or vim (powerful editor, very lightweight, steep learning curve). Other people use Spyder, emacs, gedit, Notepad++, Sublime, Atom…

You will also need to understand how git works. git is a decentralized version control system that preserves the history of the software, helps tracking changes and allows for multiple versions of the code to exist at the same time. If you are new to git and version control, I recommend following the Try Git tutorial.

If you already know how all this works and would like to contribute new features then that’s awesome! Before rushing out though please make sure it is within the scope of the library so you don’t waste your time - email us or chat with us on Riot!.

If the feature you suggest happens to be useful and within scope, you will probably be advised to create a new wiki page with some information about what problem you are trying to solve, how do you plan to do it and a sketch or idea of how the API is going to look like. You can go there to read other good examples on how to do it. The purpose is to describe without too much code what you are trying to accomplish to justify the effort and to make it understandable to a broader audience.

All new features should be thoroughly tested, and in the ideal case the coverage rate should increase or stay the same. Automatic services will ensure your code works on all the operative systems and package combinations einsteinpy support - specifically, note that einsteinpy is a Python 3 only library.

Development environment

These are some succint steps to set up a development environment:

  1. Install git on your computer.

  2. Register to GitHub.

  3. Fork einsteinpy.

  4. Clone your fork.

  5. Install it in development mode using pip install --editable /path/to/einsteinpy/[dev] (this means that the installed code will change as soon as you change it in the download location).

  6. Create a new branch.

  7. Make changes and commit.

  8. Push to your fork.

  9. Open a pull request!

Code Linting

To get the quality checks passed, the code should follow some standards listed below:

  1. Black for code formatting.

  2. isort for imports sorting.

  3. mypy for static type checking.

But to avoid confusion, we have setup tox for doing this in one command and doing it properly! Run:

$ cd einsteinpy/
$ tox -e reformat

And it will format all your code!