Real Python Podcast E318 Title Image

Episode 318: Free-Threaded Python: Why Python Devs Should Know About the ABI

The Real Python Podcast

Nov 06, 2026 1h 8m intermediate community numpy

Why should every Python developer know about the CPython ABI? This week on the show, we speak with Nathan Goldbaum about free-threaded Python and the changes to the Python Application Binary Interface.

Episode Sponsor:

Nathan recently joined the CPython core developer team and has been building community support for free-threaded Python. Nathan shares his NumPy background and his work on shipping a new DType in NumPy 2.0. He also discusses his work on PyO3 and leading the effort to support thread-safe Rust extensions for use with the free-threaded build of Python.

This episode is sponsored by PropelAuth.

Topics:

  • 00:00:00 – Introduction
  • 00:01:51 – The evolution of Free-Threaded Python
  • 00:03:42 – Changes to the Application Binary Interface
  • 00:05:16 – Improving the garbage collector
  • 00:07:04 – Why should developers know about the ABI?
  • 00:11:31 – What has changed with ABI?
  • 00:19:42 – Sponsor: PropelAuth
  • 00:20:18 – Python 3.13 and the updated PyObject
  • 00:23:15 – EuroPython talk - What Every Python Developer Should Know About the ABI
  • 00:31:13 – How did you get involved with NumPy?
  • 00:35:33 – Video Course Spotlight
  • 00:37:24 – Working on NumPy conference talk
  • 00:42:23 – LLMs, aesthetic taste, and intentional software design
  • 00:43:16 – Working on NumPy 2.0, DTypes, and building the String DType
  • 00:54:43 – The stages of intentional design
  • 00:57:34 – How does it connect to working on the ABI?
  • 00:59:11 – Rust, PyO3, and the Spinning Jenny Project
  • 01:04:03 – What are you excited about in the world of Python?
  • 01:05:23 – What do you want to learn next?
  • 01:06:34 – How can people follow your work online?
  • 01:06:50 – Thanks and goodbye

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