I just published the 2nd part of the "Inside SPy" series. In this part, we will look at language semantics and what makes SPy "special" and different than CPython: phases of execution, redshifting, static typing, and metaprogramming.
antocuni.eu/2026/03/25/i...
20 years ago I did my first OSS commit.
Turned out to be a pretty good decision :)
antocuni.eu/2026/03/22/m...
@simonwillison.net this 100% matches my experience. Claude seems very good at writing SPy, which is by design *very* similar to python.
Even better, my "CLAUDE_spy.md" was generated by claude itself by looking at few thousands of lines existing spy code.
Extra info here:
github.com/spylang/demo...
After weeks of procrastination, I finally wrote the first post in a series explaining SPy.
This one focuses on why Python is slow—the gap between what the language allows and how it’s used in practice—and hints at how SPy aims to fix it:
antocuni.eu/2025/10/29/i...
The SPy project is kicking off community calls! 🎙️
Join us tomorrow (Oct 7th, 17:30 CEST) on Discord to chat, ask questions, and meet other SPy folks. Everyone’s welcome! 💚 🥸
Discord link: discord.gg/ZN4afjvq?eve...
Google calendar link: lnkd.in/d3U62QNn
Last week I was lucky to take part in the CPython Core Dev Sprint.
This is a summary of what I did, including an annotated and extended version of my talk on tracing JITs in real-world Python scenarios, plus some comparisons between PyPy’s JIT and CPython’s new JIT.
👉 antocuni.eu/2025/09/24/t...
Accessing `obj.x` in Python might look trivial — but under the hood lies a surprisingly intricate chain of logic.
I wrote an annotated walkthrough of the CPython source code that makes it all happen:
antocuni.eu/2025/08/25/i...
🛑⚠️ Claude code modified my .bashrc without asking? ⚠️🛑
It seems to that during an automatic update, claude sneakily modified my ~/.bashrc to remove an alias to itself.
I didn't ask my permission, it didn't notify me of the change.
I find it completely unacceptable.
antocuni.eu/2025/07/07/c...
Yesterday I talked about SPy at @pyconit.bsky.social
Links to slides & videos here:
antocuni.eu/2025/05/31/s...
My language is brand new and experimental, but they already named a museum after it
github.com/spylang/spy
Wow, I'm at the same time happy, surprised and honored that my PyCon US talk about SPy (github.com/spylang/spy)
made the top 10
I'm having mixed results with claude code. It seems very good at "easy tasks", but the most annoying thing is that it has the tendency to not follow my instructions and do "what it wants".
TL;DR: I put instructions in `CLAUDE.md` but it tends to forget about them:
antocuni.eu/2025/03/16/t...
👋
I wrote a small tool to automatically record all my "claude code" sessions and export them into easily shareable HTML:
github.com/antocuni/cla...
Example log:
antocuni.github.io/files/claude...
Last week @lukasz.langa.pl and Hoot Chatham visited me on the Italian Alps for a week of hacking and winter sports. This is the report:
antocuni.eu/2025/02/26/o...
SPOILER ALERT: it contains tons of PRs to CPython, Pyodide and SPy.
Fast on the heels of the last release, I have published a PyPy v7.3.19 bug-fix release with PyPy2.7, PyPY3.10 and a beta-quality PyPy3.11. Please try it out! The complete release note is at doc.pypy.org/en/latest/re...
I spent last week in Valtournenche with @antocuni.bsky.social and Hood Chatham and managed to use SPy to accelerate my #Python code in the browser. It's too early for general adoption, but not too early to get excited!
lukasz.langa.pl/f37aa97a-9ea...
Three dudes in front of snowcapped mountains.
SPy retreat in #Cervinia with @antocuni.bsky.social and Hood Chatham.