Python This Week — September 7, 2026: 3.15 Reaches Its Final Release Candidate

A busy week for the Python world: 3.15 hit its final release candidate ahead of the October launch, Django shipped a bugfix release, uv kept pace with the new interpreter, and voting opened for two Python governance bodies at once. Here's what happened over the past seven days.

Python 3.15.0 reaches release candidate 2

On September 1, the core team released Python 3.15.0rc2, the final planned preview before the stable 3.15.0 launch scheduled for October 1. It folds in roughly 144 bug fixes, build improvements, and documentation changes from 76 contributors since rc1. Only clear, reviewed bug fixes will land between now and the final release, so this is effectively the version maintainers should be testing against. Headline features for 3.15 include lazy imports, a built-in frozendict type, UTF-8 as the default encoding, and continued JIT improvements. Maintainers are strongly encouraged to publish 3.15 wheels now. source

uv 0.12.9 ships with CPython 3.15.0rc2

Astral's uv 0.12.9, released September 1, bundles the freshly minted CPython 3.15.0rc2 so you can grab the new interpreter through uv the same day it landed. The release also adds --no-locked and --no-frozen flags to disable the lock modes enabled by UV_LOCKED and UV_FROZEN for a single invocation — a small but welcome bit of per-command control. source

Django 6.1.1 bugfix release is out

The Django team issued Django 6.1.1 on September 2, a maintenance release addressing bugs in the 6.1 series. Packages and checksums are available from the downloads page and PyPI. The release follows Django's recently announced move to an annual release cadence, so staying current on point releases is the main upgrade path between major versions. source

PSF Board and inaugural Packaging Council elections open

Voting opened September 1 and runs through September 15 (2:00 pm UTC) for both the 2026 PSF Board election and the inaugural Python Packaging Council election, held in parallel. The Packaging Council is a new technical decision-making body for the interoperability specs that govern how Python packages are built, distributed, and installed; its first election fills all five seats from a field of 17 nominees. Eligible PSF voting members who affirmed their status should have a ballot link from OpaVote. source

Polars 1.44 lands with Iceberg and SQL upgrades

Polars 1.44 arrived in late August with Apache Iceberg schema evolution on sink, an adaptive rate limiter for cloud I/O, and support for correlated subqueries in the SQL layer. The dataframe library continues to push on cloud-native workflows and SQL parity, reinforcing its position as the go-to fast alternative to pandas for larger workloads. source

That's the week in Python. See you in the next digest. 🐍