Python 313 Release Notes Verified !new!

: Can be enabled at build time using the flag --enable-experimental-jit . 2. Developer Experience & REPL Upgrades

Do not use this in production. But if you are a library maintainer, now is the time to test your C extensions for thread-safety.

Prompts, tracebacks, and help menus now feature automatic colorization for better readability.

A preliminary JIT compiler that provides a foundation for future significant performance gains. python 313 release notes verified

: Pressing the up arrow now recalls an entire multi-line code block (such as a full function definition or loop) as a single entity, allowing for effortless structural edits.

The Interactive Interpreter (REPL) has received its first major overhaul in years, inspired by the PyPy interpreter and IPython.

Python 3.13 removes several long-deprecated features. If you maintain code from the Python 2 era, pay attention. : Can be enabled at build time using

Python 3.13, released on , is a transformative update focused on performance, concurrency, and developer ergonomics. It introduces landmark experimental features that lay the foundation for a "GIL-free" and faster future for CPython.

For a full list of deprecations and removals, see the official cpython/Doc/whatsnew/3.13.rst at main on GitHub.

>>> unknown_var NameError: name 'unknown_var' is not defined. Did you mean: 'unknown_var_x'? But if you are a library maintainer, now

Python 3.13 includes a preliminary architecture based on a "copy-and-patch" model.

: Multi-threaded Python scripts can scale across multiple CPU cores natively.

A vastly improved REPL based on PyPy, featuring multi-line editing, color support, and colorized tracebacks by default.

It is crucial to manage expectations here. The performance team has been transparent that this is the foundation for future improvements. The speedups in this initial release are modest—in the range of 2–5% in many benchmarks—and the JIT is currently . To enable it, you must compile CPython from source with specific flags. This is not yet a feature you can simply toggle on in a standard installer, but its inclusion is the first step towards a future where Python code can run significantly faster.