Python 3.15.0 beta 1 is here!

Python 3.15.0 beta 1 has been released, marking the first of four planned beta releases and the feature freeze milestone. Key new features 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, and several type system improvements (TypedDict with typed extra items, TypeForm, disjoint bases). The JIT compiler has been significantly upgraded with 8-9% performance improvement on x86-64 Linux and 12-13% speedup on AArch64 macOS. The release also brings stable ABI for free-threaded builds and improved error messages. Third-party maintainers are strongly encouraged to test their projects against this beta and report issues. Production use is not recommended until 3.15.0rc1.