---
id: cytriangle
version: "3.0.2"
license: LGPL 3.0
license_treatment: copyleft
maintenance: aging
---

# cytriangle — Object-oriented Cython wrapper of Shewchuk's Triangle Library

License: copyleft · Maintenance: aging · Downloads: 74.2K/mo

## What it is and what it does

CyTriangle is a Cython-based wrapper around Jonathan Shewchuk's Triangle library, a well-established tool for generating Delaunay triangulations, constrained Delaunay triangulations, Voronoi diagrams, and high-quality triangular meshes. The wrapper provides an object-oriented Python interface to make Triangle's functionality more accessible and easier to inspect and modify within Python workflows.

The package targets scientific and engineering applications, particularly finite element analysis where mesh quality is critical. It depends on numpy and is distributed as compiled wheels for Python 3.11–3.14 across macOS, Linux, and Windows. The project is in beta status with aging maintenance, but remains unarchived and has received no reported security vulnerabilities.

Use it for:

- Generate high-quality triangular meshes for finite element analysis simulations.
- Compute Delaunay triangulations and Voronoi diagrams for computational geometry tasks.
- Create constrained triangulations where certain edges or regions must be preserved in the mesh.
- Build mesh preprocessing pipelines in Python that require quality control and angle constraints.
- Inspect and modify triangle mesh objects programmatically after generation.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

CyTriangle wraps Jonathan Shewchuk's Triangle library via Cython to generate Delaunay triangulations, constrained Delaunay triangulations, Voronoi diagrams, and high-quality triangular meshes suitable for finite element analysis.

Yes, if you need Delaunay triangulation or mesh generation for finite element analysis or computational geometry. The package is stable (beta status, no known vulnerabilities), supports current Python versions, and wraps a mature underlying library. Install friction is moderate due to compiled wheels. The copyleft LGPL 3.0 license requires attention if you plan to distribute derivative work. Maintenance is aging but the repository remains active.

## Install

pip install cytriangle
uv add cytriangle
poetry add cytriangle

## Installing cytriangle

Before you install: Medium install friction due to compiled wheels for Python 3.11–3.14 on macOS, Linux, and Windows. Maintenance is aging—last commit was 2026-01-22—but the repository remains active and unarchived.

License in practice: Licensed under LGPL 3.0 (copyleft). Any derivative work or modification must be distributed under compatible terms; static linking or proprietary use may require legal review.

Quickstart:

pip install cytriangle
import cytriangle
# Create a Triangle instance and generate a mesh
tri = cytriangle.Triangle()
tri.triangulate()

Requires Python 3.11 or later; compiled wheels are provided for common platforms but source builds may require a C compiler.

Verify before relying:

- Whether the object-oriented interface supports direct inspection and modification of triangle mesh properties beyond what the underlying Triangle library exposes.
- Performance characteristics and memory overhead of the Cython wrapper compared to direct Triangle library calls.
- Availability and completeness of documentation for the wrapper's API.

## Package facts

- License: LGPL 3.0 (copyleft)
- Python support: supports_current
- Install friction: medium
- Maintenance: aging
- Downloads: 74.2K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

delaunay triangulation python, triangular mesh generation, voronoi diagram library, finite element mesh, constrained triangulation, triangle mesh quality, cython triangle wrapper, mesh-generation, computational-geometry, finite-element

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