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FauxPy Documentation

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What is FauxPy?

FauxPy (pronounced: foh pie) is an automated fault localization tool for Python programs.
It helps developers locate the root cause of software bugs using advanced dynamic analysis techniques.

FauxPy is open-source and available on GitHub.
This documentation provides installation steps, usage instructions, and API details.

New in FauxPy: LLM-Driven MBFL 🚀

FauxPy now supports LLM-Driven Mutation-Based Fault Localization!
This functionality is the result of integrating PyLLMut into FauxPy.
Check out Example 2 on the Quick Start page to see this new feature in action.

Features

FauxPy supports seven classic fault localization techniques in four families:

  1. SBFL (spectrum-based) techniques Tarantula, Ochiai, and DStar.
  2. MBFL (mutation-based) techniques Metallaxis and Muse.
  3. PS (predicate switching) fault localization.
  4. ST (stack-trace) fault localization.

It supports fault localization at the level of statements (statement-level granularity) and at the level of functions (function-level granularity).

FauxPy is based on dynamic analysis, and works seamlessly with tests written in:

FauxPy can also leverage large language models (LLMs) to improve fault localization effectiveness.

FauxPy in Action

Watch this demo video to see FauxPy in action!
It covers:

  • Running FauxPy on real-world Python projects
  • Interpreting fault localization results
  • Best practices for debugging with FauxPy

Watch the Demo

YouTube Video Views

Explore the Documentation

  • User Guide – Learn how to install and use FauxPy effectively.
  • API Reference – Documentation of FauxPy’s main entry point and the two core classes that handle execution.