← Saturday, October 10, 2026Languages & toolsRelease

Python 3.15 adds frozendict and changes default text encoding to UTF-8

lwn.net by jzb Editor score 6/10

Python 3.15 adds sentinel and frozendict built-ins, makes UTF-8 the default encoding, and improves its experimental JIT. Engineers maintaining Python software should review the compatibility implications and startup configuration changes.

What

- Python 3.15 has been released with new sentinel and frozendict built-in types.

How

- It makes UTF-8 the default text encoding and adds package startup configuration files, alongside improvements in the experimental JIT.

Why it matters

- UTF-8 defaults and startup configuration are runtime changes engineers must account for when deploying Python applications.

Read on lwn.net →

Headline, summary, brief and diagram are written by a model from the source's own text; the link, byline and numbers come from the source. Read the original before relying on a claim.