What's New in Python 3.14.0a4

Python 3.14 introduces several significant enhancements and new features. Notably, PEP 649 implements deferred evaluation of annotations, allowing annotations to be stored and evaluated only when necessary, improving performance and usability. The new annotationlib module aids in inspecting these annotations. PEP 741 introduces a new Python Configuration C API, streamlining the initialization process and allowing for ABI-compatible changes. A new interpreter type based on tail calls has been added, which can enhance performance by 3% to 30% depending on the platform and architecture. Other improvements include enhanced error messages for unpacking assignments, a strict flag for the map() function, and better handling of incorrect usage of await in asynchronous code. New modules like annotationlib have been added, while existing modules such as argparse and concurrent.futures have received significant updates. Additionally, several features are marked for deprecation or removal in future versions, including the from __future__ import annotations directive. Overall, Python 3.14 aims to enhance performance, usability, and error handling while preparing for future developments.

- Python 3.14 introduces deferred evaluation of annotations for better performance.

- A new Python Configuration C API simplifies initialization and configuration.

- A new interpreter type based on tail calls can improve performance significantly.

- Enhanced error messages and new features in existing modules improve usability.

- Several features are deprecated or set for removal in future Python versions.