Python

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-histogram/hist initially). There’s also a new test suite helper for libraries targeting the UHI indexing spec.

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, the first required bump in many years on Unix (Windows has had required bumps more often). This release contains the multi-year smart-holder branch, multi-phase init and subinterpreter support, py::native_enum, an interface to warnings, typing improvements, and more. CMake now defaults to FindPython mode.

Support for Python 3.14, 3.14t, GraalPy, PyPy 3.11, and iOS have been added, while legacy support for Python 3.7, PyPy 3.8/3.9, and CMake <3.15 has been removed. Most deprecated features have been kept for this release, but anything producing a warning in 3.0 may be removed in a future 3.x version.

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 (experimental) pyodide-version. We now fully use enable (and PyPy requires using it), and we no longer inject setuptools and wheel in build environments. Defaults have changed, too: build is now the default frontend, manylinux_2_28 is the default manylinux image, with 32-bit linux now being opt-in. We’ve removed support for Python 3.6 and 3.7, we now require 3.11+ to run cibuildwheel itself, and EoL manylinux/musllinux images now need to be fully specified.

We’ve had some fantastic releases of cibuildwheel since my last post over 2.19, so I’ll include a few of the new features from those releases, too. I’ll also note a few of the features being worked on for future releases.

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. There’s also lots more color (including syntax highlighting in the REPL!), remote debugging, deferred evaluation of annotations, and the usual error message and performance improvements. Subintepreters are now accessible without the C-API (finally!), and free-threaded Python is no longer experimental.

Scikit-build-core 0.10 is out, and it is one of the largest releases we’ve produced in terms of new configuration options. It automatically reads your minimum CMake version, you can tell it to read your scikit-build-core minimum-version, and there are settings for many of the advanced things users used to do with scikit-build (classic), like rebuilds or pure Python fallbacks on build failures.

cibuildwheel 2.19 is out, with some very big additions. A new platform, Pyodide, has been added for building WebAssembly wheels. We’ve added CPython 3.13 free-threaded builds, now on all OS’s. And we have an opt-in speed improvement with the build[uv] build-frontend option.

We’ve had some fantastic releases of cibuildwheel since my last post over 2.10, so I’ll include a few of the new features from those releases, too, with a highlight on a larger feature that can use more explaining: inherit for overrides.