Arkouda is an open source project and we love to see new contributors! We welcome contributions via issues and pull requests.

Adding Issues

Most issues fall under the broad categories of bug reports or feature requests. If your issue doesn’t fit either of these, please add it anyway and provide as much detail as possible.

It is always a good idea to review the current issue list and make sure your issue is not already present.

Using github markdown (especially code blocks) is very appreciated.

Bug Reports

When reporting a bug, please be sure to include the following information:

  • Summary of Problem

    • What behavior did you observe when encountering the bug?

    • What behavior did you expect to observe?

    • Is this a blocking issue with no known work-arounds?

  • Steps to Reproduce

    • Please provide code that will reproduce the problem if possible. Providing simplified programs demonstrating the problem will be appreciated.

  • Configuration Information

    • What’s the output of ak.get_config()? This includes information like the ArkoudaVersion and the version of Chapel the server was built with.

Feature Requests

Be as specific as possible and provide examples when appropriate. If the requested feature is based on another library (i.e. numpy, pandas, scipy), please provide a link to their supporting documentation for reference.

Developing Arkouda

If you don’t have anything in mind, check out our outstanding issues (it’s likely a good idea to filter on the label good first issue).

If you already have an idea for a new feature or have identified a bug, add an issue before you start working on it.

Once you find or create an issue you intend to work, please leave a comment in the issue indicating that. Be sure to mention @Bears-R-Us/arkouda-core-dev for our awareness. We will then assign the issue to you to avoid anyone duplicating your work.

Need assistance or want to discuss design with someone on the Arkouda team? Add a comment tagging @Bears-R-Us/arkouda-core-dev to the issue and a developer will reach out!

We use a Git Forking Workflow and recommend developers use a simple Git Feature Branch Workflow on their own fork.

Coding Conventions and Linting


We follow the coding standards laid out in PEP8. Our Continuous Integration workflow has a linter (flake8) to verify all our python code meets these requirements.

We use isort, black, and flake8 (typically in that order) to ensure our code is consistent. We utilize a line length of 105. When running black, be sure to to use the --line-length 105 parameter.

$ isort arkouda/
Fixing arkouda/

$ black --line-length 105 arkouda/
reformatted arkouda/

All done!
1 file reformatted.

$ flake8 arkouda/

For users of pycharm there is nice interoperability with these tools.

We use numpy style doc strings. It’s a good idea to write code that looks similar to the surrounding functions.


Our Chapel code linting is checking spaces only. The linter in the CI will fail if tabs are present.

  • lowerCamelCase is used for variable names and procedures

var aX: [{0..#s}] real;
proc printIt(x) {
  • UpperCamelCase is used for class names

class Foo: FooParent {}


If you’re fixing a bug, add a test. Run it first to confirm it fails, then fix the bug, run it again to confirm it’s really fixed.

If adding a new feature, add a test to make sure it behaves properly.

Things to note:

  • If you make a new test, be sure to include test_ at the beginning. Otherwise pytest will not run it.

  • If you make a new file of tests, be sure to include the file in pytest.ini, so it will be run during a make test.

See our wiki for more info on how to run our tests and create your own:

Running python tests

# Run all tests in pytest.ini
make test

# Run all tests in the CategoricalTest class (-v will print out the test name)
python3 -m pytest tests/ -v

# Run a single test from CategoricalTest named foo_test
python3 -m pytest tests/

Running chapel tests

python3 server_util/test/ -d test

Writing Pull Requests

Before posting a pull request, be sure to test locally to catch common CI failures early. This usually includes running:

  • make test

  • make mypy

  • flake8 arkouda

Every pull request should have at least one associated issue (if there’s not one, create one!).

The issue number(s) should be listed in the title and the body using closing keywords. Using github markdown (especially code blocks) is very appreciated. When in doubt, take a look at some closed pull requests.

Closes #99999: Example Feature Request

This PR (Closes #99999):
- Implements example feature request
- Adds testing for example feature request

>>> ak.example_feature(args)
"super cool functionality!"

- It will be helpful if reviewers keep THIS in mind

Reviewing Pull Requests

For the most part, only the core dev team or those assigned should review PRs.

  • As the person who left the PR feedback, you should be the one to resolve the conversation once you decide the author has addressed the issue.

  • Try to resolve all of your feedback when you feel the PR is ready to be merged.

    • If necessary, add an issue to track any feedback which is outside the scope of the PR and link the PR comment in the issue.

Core Development Team Only

Merging Pull Requests

  • Only members of the core dev team with quite a bit of experience writing and reviewing PRs should merge pull requests. If you’re unsure, ask first.

  • Only merge PRs with 2 or more concurrent approvals from members of the core dev team with limited exceptions.

  • Only merge PRs after the CI has passed and if there are no conflicts. Ideally rebase or merge with master first.

  • We prefer to have all feedback resolved before a PR is merged.

  • If you wrote it, don’t merge it. It’s best practice for someone else to decide it’s ready to be merged.

  • To keep the commit history simple and allow for easy manipulation of PRs, we use the Squash-and-Merge functionality of GitHub’s web interface.

  • Be sure to include @pierce314159 and @Ethan-DeBandi99 as a reviewer

Release Process

New versions should only be released after the core dev team has reached a consensus. Follow our release process