Python This Week: 3.15 Hits Feature Freeze, Rust-in-CPython Looms — June 16, 2026

A quick scan of what's moving in the Python world this week — releases, proposals, and community news worth your attention.

Python 3.15 reaches feature freeze

CPython 3.15 has crossed from alpha into beta, freezing its feature set. From here to the final release the core team focuses only on bug fixes and polish. Headline features now locked in include explicit lazy imports (PEP 810) for faster startup, a built-in frozendict (PEP 814), a sentinel built-in (PEP 661), a stable ABI for free-threaded builds (PEP 803), and C-API modernization (PEPs 820 and 793). Source

A Rust-for-CPython PEP is on the way

The long-discussed proposal to allow Rust in CPython is expected to land as a draft PEP around June–July 2026, with the build-system groundwork reportedly ready. If accepted, it would target Python 3.16, whose beta 1 is currently aimed at May 2027. Source

The 3.14 line keeps shipping

The current stable series continues its steady maintenance cadence, with Python 3.14.6 now available. Worth a reminder of what 3.14 brought: officially supported free-threaded Python (PEP 779), template strings / t-strings (PEP 750), deferred annotation evaluation (PEP 649), multiple interpreters in the stdlib (PEP 734), and a new compression.zstd module (PEP 784). Source

Community: EuroPython heads to Kraków

With PyCon US 2026 wrapped, the next big gathering is EuroPython 2026, running July 13–19 in Kraków, followed by DjangoCon US 2026 in Chicago on August 24–28. Source

That's the snapshot for today — see you in tomorrow's roundup.