How to Catch a Killer Using Python’s Faulthandler

Your code may look harmless. Like your friendly neighbor who waves every morning, but deep down, it’s hiding dark secrets.

Photo by Markus Spiske on Unsplash

Imagine for a moment you’re a detective hunting down a dangerous, invisible killer lurking deep within your seemingly innocent Python script. Your code may look harmless — like your friendly neighbor who waves every morning — but deep down, it’s hiding dark secrets. You know it, I know it, and today we’re going to make that killer talk. Welcome, my dear apprentice, to the dark arts of debugging Python with faulthandler.

First things first: what is faulthandler? It’s your confession extractor, built right into Python. Whenever your script crashes and burns in mysterious ways—like a disappearing victim in a low-budget horror movie—this handy module reveals exactly where the crime took place. Let’s set up the interrogation room, shall we?

Here’s your suspicious little script. It’s innocent enough:

import ctypes

# Innocent little Python script?
def harmless_function():
    ctypes.string_at(0)  # Deliberately accessing forbidden memory
harmless_function()