New features

* PEP 779: Free-threaded Python is officially supported

* PEP 649: The evaluation of annotations is now deferred, improving the semantics of using annotations.

* PEP 750: Template string literals (t-strings) for custom string processing, using the familiar syntax of f-strings.

* PEP 734: Multiple interpreters in the stdlib.

* PEP 784: A new module compression.zstd providing support for the Zstandard compression algorithm.

* PEP 758: except and except* expressions may now omit the brackets.

Syntax highlighting in PyREPL, and support for color in unittest, argparse, json and calendar CLIs.

* PEP 768: A zero-overhead external debugger interface for CPython.

UUID versions 6-8 are now supported by the uuid module, and generation of versions 3-5 are up to 40% faster.

* PEP 765: Disallow return/break/continue that exit a finally block.

* PEP 741: An improved C API for configuring Python.

A new type of interpreter. For certain newer compilers, this interpreter provides significantly better performance. Opt-in for now, requires building from source.

Improved error messages.

Builtin implementation of HMAC with formally verified code from the HACL* project.

A new command-line interface to inspect running Python processes using asynchronous tasks.

The pdb module now supports remote attaching to a running Python process.

More details: https://docs.python.org/3.14/whatsnew/3.14.html

I've created a library that use t-strings to prevent shell injection that even works on Windows. It's written in Rust. https://github.com/aspizu/tshu

    $ uv run --with tshu python -m asyncio
    >>> from tshu import sh
    >>> username = "aspizu; rm -rf /"
    >>> await sh(t"echo {username}")
    aspizu; rm -rf /

Does the library handle arguments that begin with a dash?

Does this code print out the contents of the file named `--help`, or does it print the documentation for the `cat` command?

  filename = "--help"
  await sh(t"cat {filename}")

It's worth visiting this release page to see the adorable banner

What's new

https://docs.python.org/3.14/whatsnew/3.14.html

No GIL, and JIT enabled (even if experimental), kudos to the team.

Python, I hate to love you.