Thank you for considering contributing to Kedro! It's people like you that make Kedro such a great tool. We welcome contributions in the form of pull requests (PRs), issues or code reviews. You can add to code, documentation, or simply send us spelling and grammar fixes or extra tests. Contribute anything that you think improves the community for us all!
The following sections describe our vision and contribution process.
There is some work ahead, but Kedro aims to become the standard for developing production-ready data pipelines. To be production-ready, a data pipeline needs to be monitored, scheduled, scalable, versioned, testable and reproducible. Currently, Kedro helps you develop data pipelines that are testable, versioned, reproducible and we'll be extending our capability to cover the full set of characteristics for data pipelines over time.
The Kedro team pledges to foster and maintain a welcoming and friendly community in all of our spaces. All members of our community are expected to follow our Code of Conduct and we will do our best to enforce those principles and build a happy environment where everyone is treated with respect and dignity.
We use GitHub Issues to keep track of known bugs. We keep a close eye on them and try to make it clear when we have an internal fix in progress. Before reporting a new issue, please do your best to ensure your problem hasn't already been reported. If so, it's often better to just leave a comment on an existing issue, rather than create a new one. Old issues also can often include helpful tips and solutions to common problems.
For help with your code, if the FAQs in our documentation haven't helped you, post a question on Stack Overflow. If you tag it kedro
and python
, more people will see it and may be able to help. We are unable to provide individual support via email. In the interest of community engagement we also believe that help is much more valuable if it's shared publicly, so that more people can benefit from it.
If you're over on Stack Overflow and want to boost your points, take a look at the kedro
tag and see if you can help others out by sharing your knowledge. It's another great way to contribute.
If you have already checked the existing issues in GitHub issues and are still convinced that you have found odd or erroneous behaviour then please file an issue. We have a template that helps you provide the necessary information we'll need in order to address your query.
If you have new ideas for Kedro functionality then please open a GitHub issue with the label Type: Enhancement
. You can submit an issue here which describes the feature you would like to see, why you need it, and how it should work.
If you're unsure where to begin contributing to Kedro, please start by looking through the good first issues
and help wanted issues
on GitHub.
We focus on three areas for contribution: core
, extras
or plugin
:
core
refers to the primary Kedro libraryextras
refers to features that could be added tocore
that do not introduce too many dependencies or require new Kedro CLI commands to be created e.g. adding a new dataset to thekedro.extras.dataset
data management module. All the datasets are placed underkedro.extras.datasets
to separate heavy dependencies (e.g Pandas) from Kedrocore
components.plugin
refers to new functionality that requires a Kedro CLI command e.g. adding in Airflow functionality
Typically, we only accept small contributions for the core
Kedro library but accept new features as plugin
s or additions to the extras
module. We regularly review extras
and may migrate modules to core
if they prove to be essential for the functioning of the framework.
If your development environment is Windows, you will need to set up your environment in order to contribute. You can use the win_setup_conda
and win_setup_env
commands from Circle CI configuration to guide you in the correct way to do this.
Working on your first pull request? You can learn how from these resources:
Ensure you have done these:
- Read through the pre-requisites in the ReadTheDocs documentation.
- Run the below commands:
make install-test-requirements
make install-pre-commit
- Once the above commands have executed successfully, do a sanity check to ensure that
kedro
works in your environment:
make test
make build-docs
Note: If the tests in
tests/extras/datasets/spark
are failing, and you are not planning to work on Spark related features, then you can run a reduced test suite that excludes them. Do this by executingmake test-no-spark
.
If you picked up a code or documentation related issue, before pushing the branch to the repo and creating a Pull Request please do the below:
- for code changes:
make test
- for documentation related changes:
make build-docs
- Aim for cross-platform compatibility on Windows, macOS and Linux
- Aim for backwards compatible changes where possible, and break compatibility only in exceptional cases
- We use Anaconda as a preferred virtual environment
- We use SemVer for versioning
Our code is designed to be compatible with Python 3.6 onwards and our style guidelines are (in cascading order):
- PEP 8 conventions for all Python code
- Google docstrings for code comments
- PEP 484 type hints for all user-facing functions / class methods e.g.
def count_truthy(elements: List[Any]) -> int:
return sum(1 for elem in elements if element)
Note: We only accept contributions under the Apache 2.0 license and you should have permission to share the submitted code.
Please note that each code file should have a legal header, i.e. the content of LICENSE.md
.
There is an automated check to verify that it exists. The check will highlight any issues and suggest a solution.
We use a branching model that helps us keep track of branches in a logical, consistent way. All branches should have the hyphen-separated convention of: <type-of-change>/<short-description-of-change>
e.g. feature/io-dataset
Types of changes | Description |
---|---|
docs |
Changes to the documentation under docs/source/ |
feature |
Change which adds or removes functionality |
fix |
Non-breaking change which fixes an issue |
tests |
Changes to project unit tests/ and / or integration features/ tests |
The Kedro repository requires that you squash and merge your pull request commits, and, in most cases, the merge message for a squash merge then defaults to the pull request title.
For clarity, your pull request title should be descriptive, and we ask you to follow some guidelines suggested by Chris Beams in his post How to Write a Git Commit Message. In particular, for your pull request title, we suggest that you:
- Limit the length to 50 characters
- Capitalise the first letter of the first word
- Omit the period at the end
- Use the imperative tense
A breaking change is any change that modifies Kedro's public APIs. Examples include making a change to the signature of public functions or removing a module. Your change is not considered a breaking change if a user can upgrade their Kedro version and include your change without anything breaking in their project.
A backwards-compatible change is any change that is not a breaking change.
We aim to minimise the number of breaking changes to help keep the Kedro software stable and reduce the overhead for users as they migrate their projects. However, there are cases where a breaking change brings considerable value or increases the maintainability of the codebase. In these cases, breaking backwards compatibility can make sense.
Before contributing a breaking change, you should create an issue describing the change and justify the value gained by breaking backwards compatibility.
Deprecation is the process of retiring old code that is no longer useful and eventually removing it completely. This allows us to maintain a cleaner codebase and progress with new functionality for users. The Kedro deprecation policy is as follows:
- We reserve the right to remove deprecated public methods and properties in the next major release following the deprecation of any code.
- Deprecations apply to all public APIs, classes, and methods.
- Any public feature that is pending deprecation must raise a
DeprecationWarning
to indicate its upcoming removal. - All deprecations should be noted in the
RELEASE.md
.
All non-breaking changes go into master
, from which a minor release can be deployed at any time. Any non-breaking change should branch off from master
and be merged into master
, as explained in the contribution process below.
All breaking changes go into develop
, from which a major release can be deployed at any time. Any breaking change should branch off from develop
and be merged into develop
, as explained in the contribution process below. The develop
branch contains all commits from the master
branch, but the master
branch does not contain all the commits from develop
until the next major release.
Small contributions are accepted for the core
library:
-
Fork the project by clicking Fork in the top-right corner of the Kedro GitHub repository and then choosing the target account the repository will be forked to.
-
Create a feature branch on your forked repository and push all your local changes to that feature branch. Your feature branch should branch off from:
- `master` if you intend for it to be a non-breaking, backwards-compatible change.
- `develop` if you intend for it to be a breaking change.
-
Before submitting a pull request (PR), please ensure that unit, end-to-end tests and linting are passing for your changes by running
make test
,make e2e-tests
andmake lint
locally, have a look at the section Running checks locally below. -
Determine if your change is backwards compatible:
- For backwards compatible changes, open a PR against the `quantumblacklabs:master` branch from your feature branch.
- For changes that are NOT backwards compatible, open a PR against the `quantumblacklabs:develop` branch from your feature branch.
-
Await reviewer comments.
-
Update the PR according to the reviewer's comments.
-
Your PR will be merged by the Kedro team once all the comments are addressed.
Note: We will work with you to complete your contribution but we reserve the right to take over abandoned PRs.
You can add new work to extras
if you do not need to create a new Kedro CLI command:
-
Create an issue describing your contribution.
-
Fork the project by clicking Fork in the top-right corner of the Kedro GitHub repository and then choosing the target account the repository will be forked to.
-
Work in
extras
and create a feature branch on your forked repository and push all your local changes to that featurebranch. -
Before submitting a pull request, please ensure that unit, e2e tests and linting are passing for your changes by running
make test
,make e2e-tests
andmake lint
locally, have a look at the section Running checks locally below. -
Include a
README.md
with instructions on how to use your contribution. -
Determine if your change is backwards compatible:
- For backwards compatible changes, open a PR against the `quantumblacklabs:master` branch from your feature branch.
- For changes that are NOT backwards compatible, open a PR against the `quantumblacklabs:develop` branch from your feature branch.
-
Reference your issue in the PR description (e.g.,
Resolves #<issue-number>
). -
Await review comments.
-
Update the PR according to the reviewer's comments.
-
Your PR will be merged by the Kedro team once all the comments are addressed.
Note: We will work with you to complete your contribution but we reserve the right to take over abandoned PRs.
See the plugin
development documentation for guidance on how to design and develop a Kedro plugin
.
To run E2E tests you need to install the test requirements which includes behave
.
We also use pre-commit hooks for the repository to run the checks automatically.
It can all be installed using the following command:
make install-test-requirements
make install-pre-commit
Note: If Spark/PySpark/Hive tests for datasets are failing it might be due to the lack of Java>8 support from Spark. You can try using
export JAVA_HOME=$(/usr/libexec/java_home -v 1.8)
which works under MacOS or other workarounds. Reference
All checks run by our CI / CD servers can be run locally on your computer.
make lint
Note that you will need the dependencies installed in test_requirements.txt
, which includes memory-profiler
. If you are on a Unix-like system, you may need to install the necessary build tools. See the README.md
file in kedro.contrib.decorators
for more information.
make test
Note: We place conftest.py files in some test directories to make fixtures reusable by any tests in that directory. If you need to see which test fixtures are available and where they come from, you can issue:
pytest --fixtures path/to/the/test/location.py
behave
Our CI / CD also checks that kedro
installs cleanly on a fresh Python virtual environment, a task which depends on successfully building the docs:
make build-docs
This command will only work on Unix-like systems and requires pandoc
to be installed.
The checks will automatically run on all the changed files on each commit.
Even more extensive set of checks (including the heavy set of pylint
checks)
will run before the push.
The pre-commit/pre-push checks can be omitted by running with --no-verify
flag, as per below:
git commit --no-verify <...>
git push --no-verify <...>
(-n
alias works for git commit
, but not for git push
)
All checks will run during CI build, so skipping checks on push will not allow you to merge your code with failing checks.
You can uninstall the pre-commit hooks by running:
make uninstall-pre-commit
pre-commit
will still be used by make lint
, but will not install the git hooks.