What’s New in Python 3.11? Faster Execution, Better Tracebacks, and More

Python 3.11 New Features

Python 3.11 was officially released, bringing significant speed improvements (10‑60% faster than 3.10) and a host of language enhancements.

Error Tracebacks

Tracebacks now include decorative annotations to help users understand errors more quickly. The example shows adding a decorative annotation to a traceback by placing code in inverse.py, which raises an error when attempting to compute the reciprocal of zero.

Faster Code Execution

Through the Faster CPython project and PEP 659’s “specializing adaptive interpreter,” CPython 3.11 introduces a “quickening” step that optimizes frequently executed bytecode, yielding roughly 25% average speed gains over 3.10.

Improved Async Syntax

Task groups provide a cleaner way to run and monitor multiple asynchronous tasks, simplifying error handling compared with earlier asyncio patterns.

Enhanced Type Variables

Python 3.11 adds five new typing‑related PEPs (PEP 646, 655, 673, 675, 681), expanding support for variadic generics, optional TypedDict keys, the Self type, literal string types, and dataclass conversion.

TOML Configuration Parsing

The new tomllib module adds built‑in TOML support, allowing standard‑library parsing of TOML files without external dependencies.

Other Improvements

Faster program start‑up time.

Zero‑cost exceptions and exception groups for more efficient error handling.

Negative‑zero formatting in floating‑point output.

Additional minor enhancements to string formatting and startup.

For more detailed information, refer to the official Python 3.11 documentation.