The stable release of Python 3.15.0 arrived on October 9, featuring contributions from 1,012 developers who submitted 5,643 code changes. This version introduces significant performance improvements and new technical features compared to the previous 3.14 release.
The experimental JIT compiler received a major update. On x86-64 Linux, it delivers a 7% to 8% geometric mean performance gain over the standard interpreter. On AArch64 macOS, the speed increase reaches 11% to 12% compared to the tail-calling interpreter.
New additions include the Tachyon high-frequency statistical sampling profiler and a unified performance analysis toolkit under PEP 799. Developers can now utilize TypedDict with support for typed extra items as outlined in PEP 728.
The release enhances system observability by enabling frame pointers by default per PEP 831. Additionally, PEP 788 adds protection against premature object finalization in the C API, while PEP 803, 820, and 793 provide a stable ABI for free-threaded builds.
