ridgeplot

Imported from tpvasconcelos/ridgeplot (AGENTS.md). Install upstream with npx skills add tpvasconcelos/ridgeplot. Copyright stays with the author.

ridgeplot Development Guide for AI Agents

ridgeplot is a Python package for beautiful, interactive ridgeline plots built on Plotly.

Start Here

• Read this file first, then the most relevant source file(s).
• Prefer local docs and tests over memory; do not guess behavior.
• If requirements are unclear or risky, ask a concrete question before changing code.

Stack and Style Constraints

• Python >=3.10
• Plotly graph objects (dependency is plotly>=5.20)
• Line length 100, formatting with ruff
• Docstrings are NumPy style
• Type annotations are modern and throughout with strict checking via pyright

Quick Commands

Environment Setup

# Initialize full development environment (recommended for first-time setup)
# This creates .venv, installs dependencies, and sets up pre-commit hooks
make init

# Activate the virtual environment
source .venv/bin/activate

Running Tests

# Run all test suites (unit + e2e + cicd_utils)
uvx tox -m tests

# Run a specific test suite
uvx tox -e tests-unit        # Unit tests with coverage
uvx tox -e tests-e2e         # End-to-end tests
uvx tox -e tests-cicd_utils  # CI/CD utilities tests

# Run pytest directly with custom options
uvx tox -e pytest -- tests/unit/test_init.py --no-cov
uvx tox -e pytest -- -k "test_specific_function" --no-cov

Linting and Formatting

# Run the main static checks
uvx tox -m static-quick

# Run the entire suite of static checks (incl. all pre-commit hooks)
# If running from the main branch, you'll need
# to skip the 'no-commit-to-branch' check with:
SKIP='no-commit-to-branch' uvx tox -m static

# Run all pre-commit hooks on all files
uvx pre-commit run --all-files

# Run specific pre-commit hooks
uvx pre-commit run ruff-format --all-files

# Run type checking with pyright only
uvx tox -e typing

Documentation

# Build static documentation
uvx tox -e docs-static

Project Map

src/ridgeplot/
├── __init__.py           # Public API exports
├── _ridgeplot.py         # Main ridgeplot() function
├── _figure_factory.py    # Plotly Figure construction
├── _kde.py               # Kernel Density Estimation
├── _hist.py              # Histogram binning
├── _types.py             # Type aliases and type guards
├── _utils.py             # Utility functions
├── _missing.py           # Sentinel for missing values
├── _version.py           # Version string (setuptools-scm)
├── _color/               # Color handling
│   ├── colorscale.py     # Colorscale resolution
│   ├── css_colors.py     # CSS color parsing
│   ├── interpolation.py  # Color interpolation
│   └── utils.py          # Color utilities
├── _obj/traces/          # Trace objects
│   ├── area.py           # Area trace (filled curves)
│   ├── bar.py            # Bar trace (histograms)
│   └── base.py           # Base trace class
├── _vendor/              # Vendored dependencies
└── datasets/             # Built-in datasets
    └── data/             # CSV data files

tests/
├── conftest.py           # Shared pytest fixtures
├── unit/                 # Unit tests for individual modules
├── e2e/                  # End-to-end tests with expected outputs
│   └── artifacts/        # JSON artifacts for e2e comparisons
└── cicd_utils/           # Tests for CI/CD utilities

cicd_utils/               # CI/CD helper modules
├── cicd/                 # Scripts and test helpers
└── ridgeplot_examples/   # Example implementations for docs/testing

Public API

The public API exposes one main function: ridgeplot.ridgeplot(...) -> go.Figure

The ridgeplot() docstring in src/ridgeplot/_ridgeplot.py contains the API contract.

ridgeplot.datasets.load_probly() and ridgeplot.datasets.load_lincoln_weather() are legacy loaders kept for backwards compatibility only.

Key Data Flow

1. Users call ridgeplot(samples=...) or ridgeplot(densities=...).
2. If samples are provided, KDE in _kde.py or histogram binning in _hist.py produces densities.
3. Densities are normalised if the norm parameter is set.
4. create_ridgeplot() in _figure_factory.py builds the Plotly Figure by resolving colors, creating traces, and applying layout settings.
5. The function returns a plotly.graph_objects.Figure.

Key Files to Know

Documentation: https://ridgeplot.readthedocs.io/en/stable/

Workflow Expectations

When Adding New Features

1. Start with src/ridgeplot/_ridgeplot.py to understand the entry point.
2. Add parameters following existing patterns and deprecation handling.
3. Update types in src/ridgeplot/_types.py when introducing new structures.
4. Add tests in tests/unit/ with good coverage.
5. Update docstrings to match the new behavior.

When Fixing Bugs

1. Write a failing test first.
2. Fix the issue with minimal changes.
3. Ensure tests and type checks pass.
4. Verify docstrings remain accurate.

Type Annotations

• Uses pyright in strict mode (see pyrightconfig.json)
• All functions must be fully typed, following modern Python typing practices and existing project conventions.
• Use TYPE_CHECKING blocks for import-only types
• Use type guards for runtime type narrowing (see _types.py)
• Follow this general principle for user-facing code: be contravariant in the input type and covariant in the output type
• Add type aliases close to their usage. If widely used, place in _types.py.

Common Patterns

Handling deprecated parameters:

if deprecated_param is not MISSING:
    if new_param is not None:
        raise ValueError("Cannot use both...")
    warnings.warn("...", DeprecationWarning, stacklevel=2)
    new_param = deprecated_param

Type narrowing with guards:

if is_shallow_samples(samples):
    samples = nest_shallow_collection(samples)
samples = cast("Samples", samples)

Lazy imports for performance:

# Heavy imports inside functions to reduce import time
def _coerce_to_densities(...):
    from ridgeplot._kde import estimate_densities  # statsmodels is slow to import

Testing Notes

• Use --no-cov flag during development for faster test runs
• Run targeted tests via: uvx tox -e pytest -- tests/unit/test_foo.py -k "test_bar" --no-cov
• The tests/e2e/artifacts/ directory contains expected Plotly Figure JSON for e2e tests

CI/CD Pipeline

GitHub Actions runs tests on Python 3.10–3.14 across Ubuntu, macOS, and Windows. Codecov minimums are 100% overall and 100% diff coverage for new code. Intentionally-untested lines must carry an explicit # pragma: no cover comment.

Notes for AI Assistants

1. Run tests after changes when feasible, starting with the smallest relevant subset.
2. Run uvx tox -e typing if types are touched or errors are likely.
3. Run uvx pre-commit run ruff-format --all-files to format code.
4. Preserve deprecation behavior and public API stability.
5. Keep changes minimal and aligned with existing patterns.
6. Respect existing patterns - this is a mature codebase with consistent style.