Python 3.15.0 beta 3 is here!
Python 3.15.0 beta 3 has been released, the third of four planned beta releases before the final version. It includes around 195 bugfixes, build improvements, and documentation changes from 86 contributors. Key features in Python 3.15 include PEP 810 explicit lazy imports for faster startup, a new frozendict built-in type, a sentinel built-in type, a dedicated profiling package with the Tachyon high-frequency statistical sampling profiler, frame pointers enabled by default, unpacking in comprehensions, UTF-8 as the default encoding, TypedDict with typed extra items, TypeForm annotations, and a significantly upgraded JIT compiler delivering 8-9% performance improvement on x86-64 Linux and 12-13% on AArch64 macOS. The next beta (b4) is scheduled for 2026-07-18, with the release candidate phase starting 2026-08-04. Production use is not recommended until 3.15.0rc1.