OpenMMLab welcomes everyone who is interested in contributing to our projects and accepts contribution in the form of PR.
What is PR¶
PR is the abbreviation of
Pull Request. Here’s the definition of
PR in the official document of Github.
Pull requests let you tell others about changes you have pushed to a branch in a repository on GitHub. Once a pull request is opened, you can discuss and review the potential changes with collaborators and add follow-up commits before your changes are merged into the base branch.
Get the most recent codebase
Checkout a new branch from
dev-1.xbranch, depending on the version of the codebase you want to contribute to.
Commit your changes (Don’t forget to use pre-commit hooks!)
Push your changes and create a PR
Discuss and review your code
Merge your branch to
Procedures in detail¶
1. Get the most recent codebase¶
When you work on your first PR
Fork the OpenMMLab repository: click the fork button at the top right corner of Github page
Clone forked repository to local
git clone firstname.lastname@example.org:XXX/mmocr.git
Add source repository to upstream
git remote add upstream email@example.com:open-mmlab/mmocr
After your first PR
Checkout the latest branch of the local repository and pull the latest branch of the source repository. Here we assume that you are working on the
git checkout dev-1.x git pull upstream dev-1.x
2. Checkout a new branch from
git checkout -b branchname
To make commit history clear, we strongly recommend you checkout the
dev-1.x branch before creating a new branch.
3. Commit your changes¶
If you are a first-time contributor, please install and initialize pre-commit hooks from the repository root directory first.
pip install -U pre-commit pre-commit install
Commit your changes as usual. Pre-commit hooks will be triggered to stylize your code before each commit.
# coding git add [files] git commit -m 'messages'
Sometimes your code may be changed by pre-commit hooks. In this case, please remember to re-stage the modified files and commit again.
4. Push your changes to the forked repository and create a PR¶
Push the branch to your forked remote repository
git push origin branchname
Create a PR
Revise PR message template to describe your motivation and modifications made in this PR. You can also link the related issue to the PR manually in the PR message (For more information, checkout the official guidance).
Specifically, if you are contributing to
dev-1.x, you will have to change the base branch of the PR to
dev-1.xin the PR page, since the default base branch is
You can also ask a specific person to review the changes you’ve proposed.
5. Discuss and review your code¶
Modify your codes according to reviewers’ suggestions and then push your changes.
6. Merge your branch to
dev-1.x branch and delete the branch¶
After the PR is merged by the maintainer, you can delete the branch you created in your forked repository.
git branch -d branchname # delete local branch git push origin --delete branchname # delete remote branch
Use pre-commit hook to avoid issues of code style
One short-time branch should be matched with only one PR
Accomplish a detailed change in one PR. Avoid large PR
Bad: Support Faster R-CNN
Acceptable: Add a box head to Faster R-CNN
Good: Add a parameter to box head to support custom conv-layer number
Provide clear and significant commit message
Provide clear and meaningful PR description
Task name should be clarified in title. The general format is: [Prefix] Short description of the PR (Suffix)
Prefix: add new feature [Feature], fix bug [Fix], related to documents [Docs], in developing [WIP] (which will not be reviewed temporarily)
Introduce main changes, results and influences on other modules in short description
Associate related issues and pull requests with a milestone