---
id: patsy
version: "1.0.2"
license: 2-clause BSD
license_treatment: permissive
maintenance: active
---

# patsy — A Python package for describing statistical models and for building design matrices.

License: permissive · Maintenance: active · Popularity: top 1,000 on PyPI

## Install

pip install patsy
uv add patsy
poetry add patsy

## Description

# Patsy

**Notice:** `patsy` is no longer under active development. As of August 2021,
Matthew Wardrop (@matthewwardrop) and Tomás Capretto (@tomicapretto) have taken
on responsibility from Nathaniel Smith (@njsmith) for keeping the lights on, but
no new feature development is planned. The spiritual successor of this project
is [Formulaic](https://github.com/matthewwardrop/formulaic), and we
recommend that users [migrate](https://matthewwardrop.github.io/formulaic/migration/)
when possible. For the time being, until major software packages have successfully
transitioned, we will attempt to keep `patsy` working in its current state with
current releases in the Python ecosystem.

---

Patsy is a Python library for describing statistical models
(especially linear models, or models that have a linear component) and
building design matrices. Patsy brings the convenience of [R](http://www.r-project.org/) "formulas" to Python.

[![PyPI - Version](https://img.shields.io/pypi/v/patsy.svg)](https://pypi.org/project/spec-classes/)
![PyPI - Python...

## AI interpretation — verify before relying

Patsy builds design matrices for statistical models using R-style formula syntax, enabling convenient specification of linear models and related statistical analyses in Python.

Verdict: Patsy is a mature, well-maintained library for statistical model specification that fills a specific niche in bringing R's formula convenience to Python. While no new features are planned and the project recommends Formulaic for new work, it remains actively supported for current Python versions and carries no known vulnerabilities, making it safe for existing codebases.

[View on SkillFed](https://skillfed.io/packages/patsy) · [View on PyPI](https://pypi.org/project/patsy/)