500 Lines or LessA Python Interpreter Written in Python Allison Kaptur Allison is an engineer at Dropbox, where she helps maintain one of the largest networks of Python clients in the world. Before Dropbox, she was a facilitator at the … Read more
17 Mar 2026 (JIT performance as of 17 March (PST). Lower is better versus interpreter. Image credits to https://doesjitgobrrr.com/). Great news—we’ve hit our (very modest) performance goals for the CPython JIT over a year early for macOS AArch64, and a … Read more
Empty containers like [] and {} are everywhere in Python. It’s super common to see functions start by creating an empty container, filling it up, and then returning the result. Take this, for example: def my_func(ys: dict[str, int]): x = … Read more
24 December 2025 Some time ago I posted an apology peice for Python’s tail caling results. I apologized for communicating performance results without noticing a compiler bug had occured. I can proudly say today that I am partially retracting that … Read more
The labs on this website are designed to accompany the Foundations of Applied Mathematics textbook series. They provide hands-on experience with key mathematical and computational concepts, connecting theory to practical, real-world applications. Note for public users: If you are not … Read more
TL;DR: ty is an extremely fast Python type checker and language server, written in Rust, and designed as an alternative to tools like mypy, Pyright, and Pylance. Today, we’re announcing the Beta release of ty. We now use ty exclusively … Read more
Note: This post was updated with additional details regarding AWS Lambda. Last year we announced basic support for Python Workers, allowing Python developers to ship Python to region: Earth in a single command and take advantage of the Workers platform. … Read more
This website contains the full text of the Python Data Science Handbook by Jake VanderPlas; the content is available on GitHub in the form of Jupyter notebooks. The text is released under the CC-BY-NC-ND license, and code is released under … Read more
Z3Py Guide Z3 is a high performance theorem prover developed at Microsoft Research. Z3 is used in many applications such as: software/hardware verification and testing, constraint solving, analysis of hybrid systems, security, biology (in silico analysis), and geometrical problems. This … Read more
In November of 2024 I wrote a blog post titled “Is Python Really That Slow?”, in which I tested several versions of Python and noted the steady progress the language has been making in terms of performance. Today is the … Read more