Python Tooling Blog
RSS-
If you're on mypy in 2026, Pyrefly is the obvious upgrade
Pyrefly 1.0 (May 12, 2026) makes the mechanical half of a mypy migration free. `pyrefly init` reads `mypy.ini`, writes a Pyrefly config, and baseline files keep CI green while you triage the diagnostics Pyrefly's tighter inference surfaces.
-
Python 3.14.5 rolls back the incremental garbage collector
Python 3.14.5 reverts the incremental garbage collector that shipped in 3.14.0 through 3.14.4 back to the generational collector from 3.13. Production reports of memory pressure forced the change.
-
mypy 2.0 picks parallelism over a rewrite
mypy 2.0 shipped May 6, 2026, with experimental parallel type checking via --num-workers. The release reports up to 5x faster checks with 8 workers, narrowing the gap to ty, Pyrefly, and Zuban without trading Python for Rust.
-
Locking dependencies for PEP 723 single-file scripts in May 2026
PEP 723 made single-file Python scripts shareable. Reproducibility is still half-solved. Here's what actually works in May 2026.
-
Ruff Already Rewrites Your Python to Be More Idiomatic
Ruff's FURB rules catch non-idiomatic patterns and auto-fix them into cleaner Python. 36 rules, all with auto-fix, and most projects haven't enabled them.
-
Lightning Got Owned: When `import lightning` Steals Your Credentials
Malicious lightning PyPI versions 2.6.2 and 2.6.3 shipped a daemon-thread payload that runs on import, steals credentials, and worms into npm.
-
What Reddit taught me about why people switch to uv
A 476-upvote r/Python thread asked 'But really, why use uv?' The OP was a casual user who only installs packages a few times a month. The comments convinced them anyway.
-
ty and pyrefly find different bugs
Running ty 0.0.32 and pyrefly 0.62.0 on Textualize/rich raised 49 errors from ty and 20 from pyrefly. The 2.5x gap mostly disappears once you account for how each tool handles `# type: ignore` comments. Each tool also catches real bugs the other misses.
-
Did pip 26 close the gap with uv?
pip 26.0 shipped two flagship uv features in January 2026: PEP 723 inline scripts and --uploaded-prior-to. Here's where the actual gap sits in April 2026.
-
How Astral Uses Its Own Tools
A teardown of the ruff, ty, and uv repositories shows how Astral wires its own toolchain into the projects that produce it.