Developer’s Guide

• Contributing
  • Ways to contribute
  • Automated Contributions Policy
  • Submitting a bug report or a feature request
    • How to make a good bug report
  • Contributing code and documentation
    • Development workflow
    • Pull request checklist
    • Continuous Integration (CI)
      • Commit message markers
      • Resolve conflicts in lock files
    • Stalled pull requests
    • Stalled and Unclaimed Issues
    • Issues for New Contributors
    • Video resources
  • Documentation
    • Building the documentation
    • Generated documentation on GitHub Actions
  • Testing and improving test coverage
  • Monitoring performance
  • Issue Tracker Tags
  • Maintaining backwards compatibility
    • Deprecation
    • Change the default value of a parameter
  • Code Review Guidelines
  • Reading the existing code base
• Set up your development environment
  • Fork the scikit-learn repository
  • Set up a local clone of your fork
  • Set up a dedicated environment and install dependencies
  • Install editable version of scikit-learn
• Crafting a minimal reproducer for scikit-learn
  • Good practices
    • Provide a failing code example with minimal comments
    • Boil down your script to something as small as possible
    • DO NOT report your data unless it is extremely necessary
    • Use markdown formatting
  • Synthetic dataset
    • NumPy
    • Pandas
    • make_regression
    • make_classification
    • make_blobs
    • Dataset loading utilities
• Developing scikit-learn estimators
  • APIs of scikit-learn objects
    • Different objects
    • Estimators
      • Instantiation
      • Fitting
      • Estimated Attributes
      • Universal attributes
  • Rolling your own estimator
    • get_params and set_params
    • Cloning
    • Estimator types
    • Estimator Tags
  • Developer API for set_output
  • Developer API for check_is_fitted
  • Developer API for HTML representation
  • Coding guidelines
    • Input validation
    • Random Numbers
    • Numerical assertions in tests
• Developers’ Tips and Tricks
  • Productivity and sanity-preserving tips
    • Folding and unfolding outdated diffs on pull requests
    • Checking out pull requests as remote-tracking branches
    • Display code coverage in pull requests
    • Useful pytest aliases and flags
    • Standard replies for reviewing
    • Debugging CI issues
      • Using a lock-file to get an environment close to the CI
  • Debugging memory errors in Cython with valgrind
  • Building and testing for the ARM64 platform on a x86_64 machine
  • The Meson Build Backend
• Utilities for Developers
  • Validation Tools
  • Efficient Linear Algebra & Array Operations
  • Efficient Random Sampling
  • Efficient Routines for Sparse Matrices
  • Graph Routines
  • Testing Functions
  • Multiclass and multilabel utility function
  • Helper Functions
  • Hash Functions
  • Warnings and Exceptions
• How to optimize for speed
  • Python, Cython or C/C++?
  • Profiling Python code
  • Memory usage profiling
  • Using Cython
  • Profiling compiled extensions
    • Using yep and gperftools
    • Using a debugger, gdb
    • Using gprof
    • Using valgrind / callgrind / kcachegrind
      • kcachegrind
  • Multi-core parallelism using joblib.Parallel
  • A simple algorithmic trick: warm restarts
• Cython Best Practices, Conventions and Knowledge
  • Tips for developing with Cython in scikit-learn
    • Tips to ease development
    • Tips for performance
    • Using OpenMP
      • Types
• Miscellaneous information / Troubleshooting
  • Notes on OpenMP
  • Notes on Conda
  • Note on dependencies for other Linux distributions
  • Notes on Meson
• Bug triaging and issue curation
  • Working on issues to improve them
  • Working on PRs to help review
  • Triaging operations for members of the core and contributor experience teams
  • A typical workflow for triaging issues
• Maintainer Information
  • Releasing
    • Reference Steps
  • Updating Authors List
  • Guideline for bumping minimum versions of our dependencies
  • Merging Pull Requests
  • The scikit-learn.org Website
  • Experimental Features
• Developing with the Plotting API
  • Plotting API Overview
  • Plotting with Multiple Axes