Relevant changes in recent versions:
| Version | Change |
|---|---|
| 3.11 | TaskGroup, asyncio.timeout, exception groups and except*, tomllib; 25% faster than 3.10 on the pyperformance suite by the release’s own measurement, and 10-60% depending on the workload. |
| 3.12 | New type parameter syntax (def f[T]()), @override, per-interpreter GIL groundwork. |
| 3.13 | Experimental free-threaded build, new REPL, JIT groundwork. |
| 3.14 | Free-threaded build officially supported (PEP 779); deferred evaluation of annotations (PEP 649); concurrent.interpreters for subinterpreters (PEP 734); colour output in argparse and tracebacks. |
| 3.15 (final expected 1 October 2026, PEP 790) | abi3t, a stable ABI for free-threaded builds (PEP 803), allowing one C extension wheel across free-threaded releases. |
References
- PEP 649 – Deferred Evaluation Of Annotations Using Descriptors — Final, 3.14.
- PEP 790 – Python 3.15 Release Schedule — the dates in the last row.
- PEP 734 – Multiple Interpreters in the Stdlib — Final, 3.14.
- PEP 779 – Criteria for supported status for free-threaded Python — Final, 3.14.
- PEP 803 – “abi3t”: Stable ABI for Free-Threaded Builds — Final, 3.15.