Heterograph

heterograph is a Python library for building, querying, and visualizing heterogeneous directed graphs ("heterographs"). It provides a convenient, Pythonic API for managing vertices, edges, and their properties, supports common graph traversals, and includes rich visualization tools for notebooks and the web.

The project is designed for exploratory graph modeling and analysis, especially when you need structured metadata on vertices and edges and interactive inspection of graph topology.

---

Key Features

• Heterogeneous directed graphs

  • Vertices and edges with arbitrary, typed properties
  • Explicit in-/out-neighbour management

• Graph algorithms

  • Depth-first search (DFS) traversal utilities
  • Topology and neighbourhood queries

• Visualization

  • Interactive web-based viewer (Flask + D3)
  • Notebook-friendly display helpers
  • Optional Graphviz export for static diagrams

• Extensible design

  • Custom initialization hooks for graphs, vertices, and edges
  • Property system (HGraphProps) for clean metadata handling

---

Project Structure

heterograph/
├── heterograph/
│   ├── hgraph.py          # Core HGraph implementation
│   ├── hgraph_props.py    # Property handling for graphs, vertices, edges
│   ├── webview.py         # Flask-based interactive web viewer
│   ├── utils/             # Notebook & display helpers
│   └── assets/            # Static JS/CSS assets for visualization
├── tests/                 # Pytest test suite
├── environment.yml        # Conda environment definition
├── pyproject.toml         # Build & packaging configuration
├── LICENSE
└── README.md

---

Installation

Create the Conda environment (recommended)

conda env create -f environment.yml
conda activate heterograph

---

Quick Start

Creating a graph

from heterograph import *

# Create an empty heterograph
g = HGraph()

# Add vertices
v1 = g.add_vx()
v2 = g.add_vx()

# Add an edge
e = g.add_edge(v1, v2)

Working with properties

# Set vertex properties
g.pmap[v1]["label"] = "Source"
g.pmap[v2]["label"] = "Target"

# Set edge properties
g.pmap[e]["weight"] = 1.0

# set graph properties
g['name'] = 'my graph'

---

Visualization

Web-based viewer

from heterograph import *

g = HGraph()

# Add vertices
v1 = g.add_vx()
v2 = g.add_vx()
g.add_edge(v1, v2)
g.view()

This launches a local Flask server with an interactive graph UI (pan, zoom, inspect vertices/edges).

---

Testing

Run the full test suite with:

pytest

Tests cover:

• Vertex and edge creation
• Neighbour queries
• DFS traversal
• Graph initialization and topology

---

See environment.yml for the full dependency list.

---

License

This project is licensed under the terms of the Apache License 2.0. See LICENSE for details.

---

Acknowledgements

• Built on top of the excellent graph-tool library
• Visualization powered by Flask and D3.js