This is an early developer preview of Python 3.15

www.python.org/downloads/release/python-3150a7/

Major new features of the 3.15 series, compared to 3.14

Python 3.15 is still in development. This release, 3.15.0a7, is the seventh of eight planned alpha releases.

Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process.

During the alpha phase, features may be added up until the start of the beta phase (2026-05-05) and, if necessary, may be modified or deleted up until the release candidate phase (2026-07-28). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.15 are still being planned and written. Among the new major new features and changes so far:

• PEP 810: Explicit lazy imports
• PEP 814: frozendict built-in type
• PEP 799: A new high-frequency, low-overhead, statistical sampling profiler and dedicated profiling package
• PEP 798: Unpacking in comprehensions with * and **
• PEP 686: Python now uses UTF-8 as the default encoding
• PEP 728: TypedDict with typed extra items
• PEP 747: Annotating type forms with TypeForm
• PEP 782: A new PyBytesWriter C API to create a Python bytes object
• The JIT compiler has been significantly upgraded, with 3-4% geometric mean performance improvement on x86-64 Linux over the standard interpreter, and 7-8% speedup on AArch64 macOS over the tail-calling interpreter
• Improved error messages
• (Hey, fellow core team member, if a feature you find important is missing from this list, let Hugo know.)

The next pre-release of Python 3.15 will be 3.15.0a8, currently scheduled for 2026-04-07.

More resources

• Online documentation
• PEP 790, 3.15 release schedule
• Report bugs at https://github.com/python/cpython/issues
• Help fund Python directly (or via GitHub Sponsors) and support the Python community

And now for something completely different

And thus, while the one ship went cheerily before the breeze, the other stubbornly fought against it; and so the two vessels parted; the crew of the Pequod looking with grave, lingering glances towards the receding Bachelor; but the Bachelor’s men never heeding their gaze for the lively revelry they were in. And as Ahab, leaning over the taffrail, eyed the homeward-bound craft, he took from his pocket a small vial of sand, and then looking from the ship to the vial, seemed thereby bringing two remote associations together, for that vial was filled with Nantucket soundings.

Enjoy the new release

Thanks to all of the many volunteers who help make Python development and these releases possible! Please consider supporting our efforts by volunteering yourself or through organisation contributions to the Python Software Foundation.

Regards from Helsinki as spring melts the snow,

Your release team,
Hugo van Kemenade
Ned Deily
Steve Dower
Łukasz Langa