Python Developer Tooling Handbook

Sync with uv: Eliminate Pre-commit Version Drift

September 26, 2025

Managing tool versions across multiple configuration files creates persistent headaches in Python development. When you upgrade ruff in your pyproject.toml, you must remember to manually update the pre-commit hook version in .pre-commit-config.yaml. This version drift causes inconsistent behavior between local development and pre-commit checks.

The sync-with-uv library solves this by automatically synchronizing tool versions between uv.lock and .pre-commit-config.yaml.

The Problem

Consider this common scenario:

# pyproject.toml
[dependency-groups]
lint = ["ruff>=0.1.0", "mypy>=1.0.0"]

# .pre-commit-config.yaml
repos:
- repo: https://github.com/astral-sh/ruff-pre-commit
  rev: v0.1.5  # Must manually sync with pyproject.toml
  hooks:
    - id: ruff

When uv lock --upgrade updates ruff to 0.1.8, the pre-commit hook stays pinned to 0.1.5. This creates confusing behavior where local checks differ from pre-commit results.

Analysis of the New Wave of Python Type Checkers

September 17, 2025

If you’re following Python’s typing ecosystem, Rob Hand’s deep dive into emerging type checkers deserves your attention. He provides the first comprehensive comparison of three new Rust-based type checkers: ty (Astral), pyrefly (Meta), and zuban (David Halter).

Key Findings

Performance is the new battleground: All three tools abandon Python implementations in favor of Rust, targeting the performance bottlenecks that plague large codebases with existing checkers.

Conformance scores don’t predict real-world utility: Hand’s analysis reveals a surprising disconnect: ty passes only 15% of the typing conformance suite’s tests, yet proves surprisingly effective for everyday Python development. This suggests the suite focuses on edge cases that most developers rarely encounter.

prek: pre-commit, but fast

September 16, 2025

pre-commit is an essential tool in my development workflow for running ruff and [other tools. However, nobody wants to wait for their commits to be saved, and pre-commit isn’t always the fastest.

prek is a Rust-based drop-in replacement that runs 10x faster while using half the disk space.

Replacing pre-commit with prek is painless:

1. Install with uv tool install prek
2. Run pre-commit uninstall && prek install

That’s it. No configuration changes, no compatibility issues.

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

August 21, 2025

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.

Google Sunsets Pytype: The End of an Era for Python Type Checking

August 21, 2025

Google announced that Pytype, their Python static type checker, will end support with Python 3.12. After 13 years of development, Google is shifting resources toward “new typing approaches” rather than continuing to maintain their bytecode-based analyzer.

Pytype’s fundamental architecture became its limitation. Built on bytecode analysis, the tool struggled with Python’s evolving type system. As Google noted, “bytecode’s inherent instability and propensity to change” made implementing new typing PEPs increasingly difficult.