Packaging 26.3 is out, with ranges (huge), PEP 808 support, and tons of fixes, improved performance, etc. github.com/pypa/packagi...

Release 26.3 · pypa/packaging

What's Changed Features Add a public VersionRange API and SpecifierSet.to_range(), representing the versions a specifier set accepts as an interval set that supports intersection, union, differenc...

github.com

cibuildwheel 4.2.0 is out, with Python 3.15rc1 across all platforms, including pyemscripten for the first time on launch day! Time to build your binary wheels for 3.15! github.com/pypa/cibuild...

Release v4.2.0 · pypa/cibuildwheel

🌟 CPython 3.15 wheels are now built by default - without the "cpython-prerelease" enable set. It's time to build and upload these wheels to PyPI! This release includes CPython 3.15.0rc1, which is g...

github.com

Released CLI11 2.7, with a strong focus on hunting down and fixing bugs, modernized docs (with the old gitbook integrated in now), and better C++26 support. cliutils.github.io/CLI11/change...

Scikit-build-core 1.0 is out! Over 90 bugs fixed, great new features (dynamic-metadata, env table, editable & rebuild improvements, force-include, and more!), and over 100 issues closed! Just in time for SIMPLE-Py next week! iscinumpy.dev/post/scikit-...

scikit-build-core 1.0

Scikit-build-core 1.0, the culmination of a four year project to build the best compiled code backend for Python, is out. It’s a huge release, with over 90 bugs fixed, over 40 new features, accounting...

iscinumpy.dev

Wrote a post on my (brief) experience with Claude Fable, reviewing dozens of repositories, finding hundreds of bugs, and making a few hundred PRs! iscinumpy.dev/post/claude-...

Claude Code Reviews with Fable

Fable came out and then disappeared a couple of days later. In that short time, I managed to run a lot of repository reviews with it, and was really happy with the results. I’ve found and fixed around...

iscinumpy.dev

If you'd like to learn about modern Python packaging (including easily shipping compiled code) from the people who work on it, we still have spots left in SIMPLE-Py! Flights and hotel are funded. You can combine it with attending SciPy 2026 if you want! www.scipy2026.scipy.org#simple-py

🎡 cibuildwheel 4.0 is out! 🌟 Pyemscripten (Pyodide on PyPI!) ✨ CPython 3.15(t), incl. iOS & Android 🔐 SHA256 verification 🌟 Windows auto-bundles extension DLLs (delvewheel) 🌟 abi3audit wheel auditing ⚠️ Drops Python 3.8 & much more! iscinumpy.dev/post/cibuild...

🎡 cibuildwheel 4.0

cibuildwheel 4.0.0 is out, with some very big additions. We’ve added pyemscripten 3.13 wheels (uploadable to PyPI!), Python 3.15 (and 3.15t) betas, and much more! We’ve got a new stage: audit, which a...

iscinumpy.dev

Plumbum 2.0 - the Python shell script helper library, is out, with async, full static typing, more pathlib API, no pywin32 dep, lazy imports, and much more! plumbum.readthedocs.io/en/latest/ch...

Announcing SIMPLE-Py, a two-day workshop on making compiled Python packages! It will be held alongside SciPy’s tutorial sessions July 13-14 at the University of Minnesota. We have funding for travel (to SciPy!), food, and lodging during the workshop. scikit-build.org/events/simpl...

My Python 3.15 what's new post is out for the just-released 3.15 beta 1! iscinumpy.dev/post/python-...

Python 3.15

Python 3.15 beta 1 is out! This is a really impactful release, with some really big additions. A new lazy import system, a powerful sampling profiler, not one but two new builtins, the usual color/typ...

iscinumpy.dev

Post on my exploration of agentic AI is up! Lots of examples from my 107 PRs made with some AI assistance in the last three months (out of 412). I've included model tags colored by OSS vs. Copilot models. The OpenCode screenshot does light/dark mode. :) iscinumpy.dev/post/startin...

Starting With Agentic AI

AI suddenly passed the “more time saved than spent” point around December 2025. A little late, I’ve finally started using agentic AI in various places over the last 2-3 months, and wanted to jot down ...

iscinumpy.dev

Packaging 26.2 is out! Quick fix for pyemscripen tags, stable and faster pickle support, and a bit of polish. This is the release in pip 26.1, which came out yesterday. It’s our last release to support Python 3.8, we’re a little behind dropping Pythons. github.com/pypa/packagi...

Release 26.2 · pypa/packaging

What's Changed Fixes: Fix incorrect sysconfig var name for pyemscripten by @ryanking13 in #1160 Make Version, Specifier, SpecifierSet, Tag, Marker, and Requirement pickle-safe and backward-compati...

github.com

Packaging 26.1 out! Another huge release, with lots of great stuff, like pyemscripten wheels, free-threading stable ABI, dependency-groups, direct-urls, more pylock, & key for filter. Benchmarking, property-based testing, 2x faster performance in places! github.com/pypa/packagi...

Release 26.1 · pypa/packaging

Features: PEP 783: add handling for Emscripten wheel tags by @hoodmane in #804 PEP 803: add handling for the abi3.abi3t free-threading tag by @ngoldbaum in #1099 PEP 723: add packaging.dependency_...

github.com

I've just released nox 2026.04.10, with --usage (full docstrings), auto-ignored `.nox` folder, and several great fixes, like auto-recreating environment if Python symlinks are broken and `-t` selecting tags from all sessions. Enjoy! github.com/wntrblm/nox/...

Release 2026.04.10 🧹 · wntrblm/nox

This release drops Python 3.8 and adds a --usage command for full docstrings. Our .nox dir is now ignored by default, virtualenvs are recreated if symlinks are broken (such as after a Python upgrad...

github.com

Great release of pip with 26.0! Colorful --help, --requirements-from-script, --uploaded-prior-to, and all the performance optimization work we did on packaging 26.0! New build environment option, too.

Packaging 26.0 is out! Hopefully in time for pip 26.0. :) github.com/pypa/packagi...

Release 26.0 · pypa/packaging

Read about the performance improvements here: https://iscinumpy.dev/post/packaging-faster. What's Changed Features: PEP 751: support pylock by @sbidoul in #900 PEP 794: import name metadata by @br...

github.com

On behalf of the packaging maintainers, I’d like to announce packaging 26.0rc1 is out! Please try it out, as it's a huge release. If you'd like to read about the performance work making this the fastest version of packaging ever, see my post: iscinumpy.dev/post/packagi...

How we made Python's packaging library 3x faster

Along with a pip (and now packaging) maintainer, Damian Shaw, I have been working on making packaging, the library behind almost all packaging related tools, faster at reading versions and specifiers,...

iscinumpy.dev

I've written a post about my experience learning TypeScript and using AI for this year's Advent of Code (after learning Rust the last two years). iscinumpy.dev/post/aoc-2025 Merry Christmas!

Advent of Code 2025 in Typescript

After two years of Advent of Code in Rust, I thought I’d try TypeScript. I’ve always wanted to improve repo-review’s webapp, and that requires knowledge of the packaging systems for JavaScript, so I t...

iscinumpy.dev

Partially dynamic project metadata: peps.python.org/pep-0808

PEP 808 – Partially dynamic project metadata | peps.python.org

This PEP relaxes the constraint on dynamic metadata listed in the [project] section in pyproject.toml to allow the static portion of mixed metadata to be defined in the normal location if the field is...

peps.python.org

cibuildwheel 3.3 out! Fix for docker 29 changing the capitalization of the version output, but also runner customization (for iOS on GHA macos-15), manylinux_2_35 on armv7l, build[uv] support on Android, removed build-system constraints, and more! github.com/pypa/cibuild...

Release v3.3.0 · pypa/cibuildwheel

🐛 Fix an incompatibility with Docker v29 (#2660) ✨ Adds test-runtime option, to customise how tests on simulated/emulated environments are run (#2636) ✨ Adds support for new manylinux_2_35 images o...

github.com

I've just finished uhi 1.0, following boost-histogram 1.6 and hist 2.9, with support for serializing histograms into JSON/ZIP/HDF5. There's also a new testing helper (libraries implementing UHI can get dozens of tests with a few lines), and much more! iscinumpy.dev/post/uhi-1-0/

UHI 1.0: histogram serialization

UHI 1.0 is out, with a major new feature: a new histogram serialization spec! This spec supports multiple formats (HDF5, zip, and JSON initially), and can be supported by multiple libraries (Boost-his...

iscinumpy.dev

cibuildwheel π is out! (3.1.4). A few nice things, like --clean-cache, Android fixes, and new versions of things like CPython 3.14rc2. Note for iOS on GHA/Azure, you need macOS-14, Microsoft broke macOS-15 images for iOS (WRT CPython's test runner, anyway) github.com/pypa/cibuild...

Release v3.1.4 · pypa/cibuildwheel

✨ Add a --clean-cache command to clean up our cache (#2489) 🛠 Update Python to 3.14rc2 and other patch version bumps (#2542, #2556) 🛠 Update Pyodide to 0.28.2 (#2562, #2558) 🐛 Fix resolution with p...

github.com

PSA: You can't use `pip install -U pip` to upgrade to pip 25.2 on Windows. You have to use `python -m pip install -U pip`. That's always been better, but now the entrypoint scripts were optimized to be faster (I've wanted this for years!), Windows doesn't PIP.EXE modify itself!

We just released cibuildwheel 3.1, which builds Python 3.14/3.14t wheels by default (with yesterday's RC 1)! Also we added Android support, Pyodide 0.28 (3.13), 32-bit modern manylinux, riscv64 defaults, and beautiful new summaries! github.com/pypa/cibuild...

Release v3.1.0 · pypa/cibuildwheel

🌟 CPython 3.14 wheels are now built by default - without the "cpython-prerelease" enable set. It's time to build and upload these wheels to PyPI! This release includes CPython 3.14.0rc1, which is g...

github.com

pybind11 3.0 is out (in time for #scipy2025)! Support for Python 3.14, 3.14t, GraalPy, PyPy 3.11, and iOS have been added. smart-holder merged, native enums, multiphase init, subinterpreters (with per-interp GIL), better typing, C++23, and much more! See iscinumpy.dev/post/pybind1...

pybind11 3.0.0

Pybind11 3.0 has been released! I would like to highlight some of the key changes below; be sure to check out the changelog and upgrade guide for more information! This release includes an ABI bump, t...

iscinumpy.dev

I've updated my Python 3.14 post with the new additions in 3.14.0b3: free-threading is no longer experimental, and concurrent.interpreters has been added! I've added a couple of examples: iscinumpy.dev/post/python-...

Python π

Python π (3.14) beta 3 is out, which means the features are locked in (normally beta 1, but two additions were made exceptionally in beta 3!). The big feature this time around is template strings. The...

iscinumpy.dev

cibuildwheel 3.0 is out! New support for Python 3.14 (and 3.14t) betas, GraalPy, and iOS! New defaults, new config options, beautiful docs updates, and more! iscinumpy.dev/post/cibuild...

🎡 cibuildwheel 3.0

cibuildwheel 3.0.0 is out, with some very big additions. We’ve added GraalPy, Python 3.14 (and 3.14t) betas, and iOS support! We’ve got several new options: test-sources, test-environment, and (experi...

iscinumpy.dev

If you are updating for Python π (Python 3.14) and are using argparse, remember to conditionally add `color=True` and, if using choices or subcommands, `suggest_on_error=True`!

The beta is out, so it's time for What's new in Python π: iscinumpy.dev/post/python-... (also it's time to start adding it to CI and adding classifiers if it works!)

Python π

Python π (3.14) beta 1 is out, which means the features are locked in.

iscinumpy.dev

The Scientific-Python Development Guide has been updated with SPDX licenses (PEP 639) and dependency-groups (PEP 735)! There's more uv, too; the cookiecutter/copier template now sets up uv everywhere for ultra fast CI. New repo-review checks, too. learn.scientific-python.org/development/...