core.py

Pablo Galindo and Łukasz Langa
  • 5.0 (20)
  • Tech News
  • Updated Biweekly

We talk about Python internals, because we work on Python internals. We joke about stuff, because we’re jokers. Episodes between 60 and 90 minutes in length. We’ve done more than a few so far and it doesn’t seem like we’ll be stopping any time soon! Hi Loren!

  1. 10h ago

    Episode 30: Live from EuroPython, an Interview with Guido van Rossum

    This one is a short one. But it's also a big one. We'd invite you to listen to it, but you don't need to follow us. You don't need to follow anybody! You've got to think for yourselves! You're all individuals! ## Timestamps (00:00:00) INTRO (00:00:36) PART 1: GUIDO VAN ROSSUM (00:01:09) Monty Python reference only GvR understood (00:01:27) Math Olympiad anniversary (00:03:31) Silly hats (00:05:20) perchance (00:09:51) PR OF THE WEEK (not really) (00:11:04) The Grail Web Browser (00:14:31) Generational gaps (00:17:24) Changes in beliefs (00:21:43) Pablo Galindo Salgado was never right (00:23:11) Aesthetics in coding (00:29:16) Rietveld (00:34:14) VScode is the new Emacs (00:35:41) On recognition outside of tech (00:38:11) Taste in music (00:39:51) Cameo in a movie? (00:40:52) OUTRO

  2. Apr 17

    Episode 29: Is CPython developed with AI now?

    Let's talk about what it really means in practice that AI tools are used in the cpython GitHub repository now. First-hand opinions based on first-party experience. And some personal news! ## Timestamps (00:00:00) INTRO (00:00:58) PART 0: Developer Leaves Residence (00:09:15) Python's got more batteries included than Łukasz ever knew (00:14:18) Camera does not respect Łukasz (00:14:43) PART 1: F*****g AI Shit (00:17:36) December 2025 crossed the usability threshold(00:18:24) Pablo wants Claude Max (00:19:24) Python on the Mastodon AI hit lists (00:25:46) Pablo needs human connection (00:28:23) GitHub now lets projects disable pull requests (00:30:35)AI disruption of the security vulnerability processes (00:34:00) Python is getting swamped with PRs, GitHub too (00:36:57) Every PR could be adversarial, AI-assisted or not (00:41:45) Pablo's prediction about reputation and time as currency (00:45:34) PART 2: PR OF THE WEEK (00:46:21) Łukasz: a Pure-Python unicodedata module? (00:57:16) Pablo: diff-based terminal rendering in PyREPL (01:12:26) Copilot reviews on GitHub (01:19:11) Debugging with AI (01:26:39) PART 3: WHAT'S GOING ON IN CPYTHON (01:26:57) Subscribe to Savannah's coredispatch.xyz (01:29:22) Python releases since last episode (01:30:45) New team members (01:31:12) PyCon US: come and book the official hotel (01:32:54) blog.python.org now looks like it was made in 2026 (01:35:27) Features (01:56:08) Free-threading changes (01:58:48) Curiosities (01:59:49) Bugfixes (02:03:55) OUTRO

  3. Jan 3

    Episode 28: 2025 In Review

    Let's take a breather from heavy content and take a look back at last year in this light but spicy episode! The good, the less good, and the disgusting. All that in barely an hour! ## Timestamps (00:00:00) INTRO (00:01:32) Pablo Galindo SPACE (00:06:20) PART 1: 2025 - the good, the uncertain, and the disgusting (00:07:06) Good: free threading (00:15:34) Good: remote debugging (00:17:31) Good: Python Installation Manager on Windows (00:19:44) The juicy bits (00:20:12) Uncertain: the JIT (00:21:04) Uncertain: Steering Council elections (00:25:01) Uncertain: another type checker (00:28:57) The TIOBE index (00:34:03) Mojo (00:38:12) Underinvestment (00:44:53) The Future (00:56:41) PART 2: PR OF THE WEEK (01:05:32) PART 3: WHAT'S GOING ON IN CPYTHON (01:08:00) Performance (01:11:47) Free threading (01:14:04) OUTRO

  4. 12/07/2025

    Episode 27: Calling Things, Part 1

    Inside of you there are two stacks. Actually, there’s three. The system-level call stack, the CPython call stack, and the interpreter’s evaluation stack. What is all that about? Today we’ll talk about how synchronous Python function calls work. Async stuff comes next time! ## Timestamps Here you go — all square brackets changed to parentheses: (00:00:00) INTRO (00:02:28) PART 1: CALLING THINGS (00:04:19) The Lawful Good Language (00:13:18) Why is there a call stack? (00:19:45) Python functions are not tied to the system call stack (00:23:22) What's in a Python frame? (00:23:35) Execution book-keeping data (00:24:21) Locals (00:27:35) The interpreter evaluation stack (00:28:34) What are register-based interpreters? (00:36:33) Interpretation using the evaluation stack (00:42:46) Executing a function (00:45:37) How do exceptions fit into the execution model? (01:05:51) PART 2: PR OF THE WEEK (01:15:48) PART 3: DONATE.PYTHON.ORG (01:17:21) PART 4: WHAT'S GOING ON IN CPYTHON (01:27:59) Free threading changes (01:38:16) Performance (01:51:08) Bugfixes (02:04:03) OUTRO

  5. 10/25/2025

    Episode 26.2: CPython Sprint Week in Cambridge UK, Part 2

    More interviews from the core sprint! This time we have: Greg P. Smith, Thomas Wouters, Paul Ganssle, Pradyun Gedam, Carol Willing, Guido van Rossum, Brett Cannon, Erlend Aasland, Tal Einat, Lysandros Nikolaou, Yury Selivanov, and Diego Russo -- the organizer himself. ## Timestamps (00:00:00) INTRO (00:01:51) Greg P. Smith (00:07:57) Thomas Wouters (00:16:33) Paul Ganssle (00:28:28) Pradyun Gedam (00:34:02) Carol Willing (00:43:32) Guido van Rossum (00:55:39) Brett Cannon (01:10:01) Erlend Aasland (01:14:05) Tal Einat (01:22:21) Lysandros Nikolaou (01:30:40) Yury Selivanov (01:45:08) Diego Russo (01:58:27) What did the hosts do? (02:17:18) OUTRO

  6. 10/15/2025

    Episode 26.1: CPython Sprint Week in Cambridge UK, Part 1

    What? What do you mean this two-and-a-half hour episode is PART 1? Well, there were fifty people at the sprint in September. We interviewed thirty of them. In Part 1 you can hear from 18 of them: Ken Jin, Alex Waygood, Russell Keith-Magee, Sam Gross, Steve Dower, Dino Viehland, Petr Viktorin, Peter Bierma, Eric V. Smith, Hugo van Kemenade, Savannah Bailey, Eric Snow, Brandt Bucher, Antonio Cuni, Larry Hastings, Hood Chatham, Victor Stinner, and Mark Shannon. ## Timestamps (00:00:00) INTRO (00:02:43) Ken Jin (00:05:28) Alex Waygood (00:08:21) Russell Keith-Magee (00:17:32) Sam Gross (00:23:25) Steve Dower (00:26:17) Dino Viehland (00:36:02) Petr Viktorin (00:40:59) Peter Bierma (00:44:24) Eric V. Smith (00:55:25) Hugo van Kemenade (00:59:39) Savannah Bailey (01:08:53) Eric Snow (01:22:02) Brandt Bucher (01:38:53) Antonio Cuni (01:48:23) Larry Hastings (02:07:54) Hood Chatham (02:12:11) Victor Stinner (02:16:23) Mark Shannon (02:22:44) OUTRO

  7. 08/26/2025

    Episode 25: A Python That Never Was

    What if some rejected PEPs were actually accepted? How would Python look today? Let's go through 10 PEPs from the past and imagine an alternative future for the language! ## Timestamps (00:00:00) INTRO (00:01:00) PART 1: What if rejected PEPs were accepted? (00:02:15) PEP 638: Syntactic Macros (00:13:53) PEP 505: None-aware operators (00:37:12) PEP 671: Late-bound function argument defaults (00:44:40) PEP 335: Overloadable Boolean Operators (00:50:53) PEP 3136: Labeled break and continue (00:52:49) PEP 463: Exception-catching expressions (01:00:58) PEP 511: API for code transformers (01:06:30) PEP 340: Anonymous block statements (01:10:30) PEP 276 and PEP 284: Alternative integer iteration (01:17:12) The do: while: loop (01:19:50) The final boss of Python syntax feature requests (01:25:33) PART 2: PR OF THE WEEK (01:36:17) Raw f-string format fixes (01:38:44) PART 3: WHAT'S GOING ON IN CPYTHON (01:40:55) Python 3.14 RC2 and Python 3.13.7 (01:43:20) Welcome to the core team, Emma (01:43:50) Welcome to the release team, Savannah (01:45:56) Free threading changes (01:47:49) Perf improvements (01:52:00) New features (01:57:20) Bugfixes (01:59:15) OUTRO

  8. 07/12/2025

    The Megahertz

    Python 3.14? That's old news. Let's talk about the first big feature of Python 3.15 -- a built-in sampling profiler for Linux, macOS, and Windows. We also cover improvements in perf support, discuss memory.python.org, and as usual, recent changes in the codebase. ## Timestamps (00:00:00) INTRO (00:02:43) PART 1: THE SAMPLING PROFILER (00:05:07) Built-in profile is bad, long live cProfile (00:10:54) Out-of-process profiling (00:12:18) Shortcuts Compromise Accuracy, Leading Eventually to Numerous Errors (00:16:07) Selfish Łukasz vs benevolent Pablo (00:23:11) How does a sampling profiler even work? (00:30:42) One meeellion huuurtzzz (00:32:40) Free threading makes it extra spicy (00:41:26) AsyncIO makes it even spicier (00:49:49) You made this? I made this (00:54:06) What if the profiled process changes during sampling? (00:57:33) Coming in October 2026 (01:04:30) PART 2: PR OF THE WEEEEEEK (01:14:14) memory.python.org launched (01:23:15) PART 3: WHAT'S GOING ON IN CPYTHON (01:26:45) Performance updates (01:30:24) Features & Curiosities (01:41:45) OUTRO

See All (31)

Ratings & Reviews

5
out of 5
20 Ratings

About

We talk about Python internals, because we work on Python internals. We joke about stuff, because we’re jokers. Episodes between 60 and 90 minutes in length. We’ve done more than a few so far and it doesn’t seem like we’ll be stopping any time soon! Hi Loren!

Information

  • Creator
    Pablo Galindo and Łukasz Langa
  • Years Active
    2023 - 2026
  • Episodes
    31
  • Rating
    Explicit
  • Copyright
    © Pablo Galindo and Łukasz Langa
  • Show Website
    core.py