Python Developer Tooling Handbook – Ruff

Ruff Already Rewrites Your Python to Be More Idiomatic

Tim Hopper — Tue, 05 May 2026 00:00:00 +0000

Open any Python codebase that’s been through a few hands and you’ll find the same fossils: a for loop adding items to a set one at a time, a conditional slice that could be removesuffix(), a two-line open()/read() that pathlib handles in one call. The code works. It passes every linter you’ve enabled. And a reviewer who knows Python well would rewrite all of it.

Ruff can already do that rewriting. It ported 36 rules from refurb into a category called FURB, and every one of them ships with an auto-fix. Most projects haven’t turned them on because Ruff’s defaults only enable Pyflakes (F) and a subset of pycodestyle (E). The rules that catch non-idiomatic patterns sit behind an opt-in flag, invisible to the people who’d benefit most.

How Astral Uses Its Own Tools

Tim Hopper — Thu, 23 Apr 2026 09:00:00 -0400

Astral runs ruff, uv, and ty inside the repos that build them. Their pyproject.toml, .pre-commit-config.yaml, and CI files are public, and a walk through the three shows how the people making ruff, ty, and uv wire their own toolchain into the projects that produce it.

Build ty from source and type-check Python with it

The ruff repository ships ty as part of its crate tree. Three CI steps build ty from source and run it against the repo’s own Python:

OpenAI to Acquire Astral

Tim Hopper — Thu, 19 Mar 2026 00:00:00 +0000

OpenAI announced today that it will acquire Astral, the company behind uv, Ruff, and ty. The Astral team will join OpenAI’s Codex group after the deal closes, subject to regulatory approval.

What this means for Codex

Codex, OpenAI’s coding agent, has grown to over 2 million weekly active users, with 3x user growth and 5x usage increase since the start of 2026. Acquiring Astral gives OpenAI direct ownership of tools that millions of Python developers already depend on. OpenAI plans to integrate Astral’s tools more deeply into Codex so the agent can interact with the toolchain developers already use.

Charlie Marsh on uv, Coding Agents, and the Changing Open Source Contract

Tim Hopper — Tue, 24 Feb 2026 12:00:00 -0500

Charlie Marsh (founder of Astral, creator of ruff, uv, and ty) joined Michael Chow and Wes McKinney on The Test Set. They covered uv’s adoption strategy, how coding agents are changing Astral’s development process, and what’s happening to open source when writing code becomes cheap.

uv’s compatibility layer was the point

When uv first shipped, it only had uv pip install and uv venv. Some people found this odd. Charlie says it was deliberate:

uv format: Code Formatting Comes to uv (experimentally!)

Tim Hopper — Thu, 21 Aug 2025 16:08:00 -0400

The latest uv release (0.8.13) quietly introduced an experimental new command that Python developers have been waiting for: uv format. This addition brings code formatting directly into uv’s toolkit, eliminating the need to juggle multiple tools for basic Python development workflows.

What is uv format?

The uv format command provides Python code formatting through uv’s interface. Under the hood, it calls Ruff’s formatter to automatically style your code according to consistent standards.

How Python's RFC Process Paved the Way for uv, Ruff, and Ty

Tim Hopper — Fri, 01 Aug 2025 15:22:00 -0400

Astral, an independent startup, has taken the Python world by storm over the last few years with three fast, robust Python developer tools:

ruff (linter and formatter)
uv (packaging and project management)
ty (static type checker, still under development)

These tools came from the mind of Charlie Marsh, who is neither a Python core developer nor directed by the Python Steering Council. While being independently developed, these tools work seamlessly within the established Python ecosystem. This success stems partly from Astral’s attention to guidelines established by the Python Enhancement Proposal (PEP) process over the last twenty-five years.

The Python Tooling Revolution

Tim Hopper — Wed, 02 Apr 2025 16:48:00 +0000

Python development is experiencing a tooling revolution thanks to Astral’s ruff and uv. Lewis Gaul’s blog examines how these tools are transforming Python workflows with exceptional speed and intelligent design.

When trying ruff check the benefits were immediately obvious: performance is incredible, provides a superset of the pylint rules, reporting of errors is very clear, configuration is straightforward, documentation is excellent…and above all else the –fix flag is a huge win to automatically fix certain rule violations.

Simple, Modern Python

Tim Hopper — Tue, 01 Apr 2025 00:00:00 +0000

Joshua Levy recently shared his enthusiasm for uv, Astral’s Python package manager, along with a practical template for new projects using this tool. His thread on X highlights both technical advantages and philosophical approaches to modern Python development.

Key Points from Levy’s UV Template

Levy has created a simple-modern-uv, Copier template that combines minimal but essential tools for Python projects:

Uses uv for package management
Incorporates ruff for linting and formatting (replacing Black and isort)
Includes mypy, codespell, and pytest
Provides GitHub Actions configuration
Uses Copier for template management

Why uv Matters Beyond Speed

While uv’s performance is impressive, Levy emphasizes that its real value lies in dependency management fundamentals:

Effective Python Developer Tooling in December 2024

Tim Hopper — Fri, 20 Dec 2024 19:25:00 +0000

I have been writing Python for 14 years next month. When I started, people were still using easy_install to install egg-based packages for Python 2.7 and nobody had heard about Conda yet, much less uv. The Python tool ecosystem has changed since. Many people are confused by the fragmentation in the ecosystem, but we have better tooling for Python today than we’ve ever had before.

A friend recently invited me to give a talk to his team about Python tooling. In the presentation, I shared some principles of Python tooling and developer efficiency, some anti-patterns I’ve observed, recommended practices, and an opinionated list of tools I like in December 2024. What follows is a summary of that talk.