Python 313 Release Notes Verified __full__

PEP 701 – Improved REPL

– Allows type narrowing in custom type guards.

: New keyboard shortcuts include F1 for help, F2 for history browsing, and F3 for a dedicated "paste mode". 2. Smarter Error Messages python 313 release notes verified

For projects requiring multi-version support, use conditional checks:

Removal of several legacy modules deprecated since Python 3.11, including cgi , telnetlib , and mailcap . PEP 701 – Improved REPL – Allows type

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.

The wave module has deprecated several outdated parameters, and various legacy ctypes behaviors have been restricted to improve cross-platform safety. Summary of Core Performance Metrics Status in 3.13 Primary Target Experimental (Opt-in) True multi-core CPU utilization JIT Compiler Experimental (Compile-time opt-in) Baseline infrastructure for future speedups New REPL Enabled by default Developer ergonomics and fast prototyping PEP 594 Removals Standard library technical debt reduction The speedups in this initial release are modest—in

You can now move up and down through multi-line code blocks using arrow keys to edit code before executing it.

: Code syntax, interactive prompts, and error tracebacks are beautifully colorized by default on supported terminals, allowing you to instantly isolate bugs visually.