Charlie Marsh (@charliermarsh) / X

Charlie Marsh

8,239 posts

Charlie Marsh

@charliermarsh

@OpenAI. Building Ruff, uv, ty, and other high-performance Python tools with the @astral_sh team.

Brooklyn, NY

github.com/charliermarsh

Born April 16

Joined March 2009

Charlie Marsh
@charliermarsh
Feb 15, 2024
Announcing uv: an extremely fast Python package installer and resolver, written in Rust. uv is designed as a drop-in alternative to pip, pip-tools, and virtualenv. With a warm cache, uv installs are near-instant. Here, it's > 75x faster than pip and pip-tools.
1.5M
Charlie Marsh
@charliermarsh
May 13, 2025
Today, we’re announcing the preview release of ty, an extremely fast type checker and language server for Python, written in Rust. In early testing, it's 10x, 50x, even 100x faster than existing type checkers. (We've seen >600x speed-ups over Mypy in some real-world projects.)
647K
Charlie Marsh
@charliermarsh
Aug 20, 2024
Today, we're shipping a series of features that move uv beyond a pip alternative, and into an end-to-end solution for managing Python projects, command-line tools, single-file scripts, and even Python itself. A single, unified tool. Like Cargo, for Python. It's very fast.
506K
Charlie Marsh
@charliermarsh
Oct 8, 2025
Python 3.14 stable dropped today! Congratulations to everyone involved. You can install it now with `uv python upgrade 3.14`.
516K
Charlie Marsh
@charliermarsh
Aug 13, 2025
Today, we're announcing our first hosted infrastructure product: pyx, a Python-native package registry. We think of pyx as an optimized backend for uv: it’s a package registry, but it also solves problems that go beyond the scope of a traditional "package registry".
561K
Charlie Marsh
@charliermarsh
Mar 8, 2025
This can't just be me, right? Battling endlessly against this text-selection behavior?
00:00
345K
Charlie Marsh
@charliermarsh
Oct 8, 2025
As of Python 3.14, the free-threaded (or no-GIL) version of the Python interpreter is no longer considered experimental.
1M
Charlie Marsh
@charliermarsh
Jan 29, 2025
We’re building a new static type checker for Python, from scratch, in Rust. From a technical perspective, it’s probably our most ambitious project yet. We’re about 800 PRs deep!
160K
Charlie Marsh
@charliermarsh
Mar 15, 2025
Oh wow, a popular GitHub Action (tj-actions/changed-files) was fully compromised. Someone committed a base64-encoded payload that runs a script that in turn prints out encoded secrets… Stay safe out there!
498K
Charlie Marsh
@charliermarsh
May 24, 2025
You can set `UV_TORCH_BACKEND=auto` and uv will automatically install the right CUDA-enabled PyTorch for your machine, zero configuration
191K
Charlie Marsh
@charliermarsh
Oct 24, 2023
Announcing the Ruff formatter: an extremely fast, Black-compatible Python formatter. Over 30x faster than Black -- and over 99.9% compatible. Try it now with `pip install ruff` and `ruff format`. astral.sh/blog/the-ruff-…
379K
Charlie Marsh
@charliermarsh
Dec 14, 2024
I actually might lose credibility for this one, but I don't think startups should be using Rust, Zig, etc. unless the technical advantages are critical or even inherent to the product. Like, if Python, JS, etc. are even options, you should probably be using Python or JS!
450K
Charlie Marsh
@charliermarsh
Aug 30, 2022
Python tooling could be much, much faster. To prove it, I'm releasing ruff, an extremely fast Python linter, written in Rust. ruff is 10-100x faster than existing solutions. It lints the entire CPython codebase in < 500ms. Try it! (`pip install ruff`) github.com/charliermarsh/…
Charlie Marsh
@charliermarsh
Jan 20, 2023
The main thing holding me back right now is that I need more mental models... If I had 5-10 more mental models, I would be unstoppable.
325K