PEP 806: Mixing Sync and Async Context Managers

How does Python 3.14 perform under a few hand-crafted benchmarks? Does the performance of asyncio scale on the free-threaded build? Christopher Trudeau is back on the show this week, bringing another batch of PyCoder’s Weekly articles and projects.

At the top of the show, we have a mountain of release news and Python Enhancement Proposals to cover. Then, we dig into a couple of articles covering the performance of Python 3.14. The first is a benchmarking comparison of the last several Python versions and their variations, including JIT and free-threaded mode. The second explores the changes in 3.14 that enable asyncio to scale on CPython’s free-threaded build.

We also share several other articles and projects from the Python community, including an introduction to NiceGUI, a free-threaded Python library compatibility checker, an exploration of what is “good taste” in software engineering, HTML templating with t‑strings, and a tool for testing Sphinx docs instantly in the browser.

Topics:

• 00:00:00 – Introduction
• 00:02:28 – Python 3.12.12, 3.11.14, 3.10.19 and 3.9.24 now available
• 00:03:08 – Python 3.13.9 is now available
• 00:03:26 – Python 3.15.0 alpha 1
• 00:04:02 – PEP 804: An External Dependency Registry and Name Mapping Mechanism
• 00:04:56 – PEP 806: Mixed Sync/Async Context Managers With Precise Async Marking
• 00:06:34 – PEP 807: Index Support for Trusted Publishing
• 00:07:21 – PEP 809: Stable ABI for the Future
• 00:08:10 – PEP 810: Explicit Lazy Imports
• 00:10:31 – Python lazy imports you can use today
• 00:10:48 – Lazy Imports Using wrapt
• 00:11:18 – Python 3.14 Is Here. How Fast Is It?
• 00:17:45 – Free-Threaded Python Library Compatibility Checker
• 00:19:54 – Scaling Asyncio on Free-Threaded Python
• 00:24:06 – Real Python 3.14 Resources
• 00:25:18 – Video Course Spotlight
• 00:26:31 – Intro to NiceGUI: Build Interactive Python Web Apps
• 00:30:22 – What Is “Good Taste” in Software Engineering?
• 00:40:52 – Try Sphinx Docs Instantly in Your Browser
• 00:43:11 – Introducing tdom: HTML Templating With t‑strings
• 00:46:21 – Thanks and goodbye

News:

• Python Insider: Python 3.12.12, 3.11.14, 3.10.19 and 3.9.24 are now available!
• Python Insider: Python 3.13.9 is now available!
• Python Insider: Python 3.15.0 alpha 1
• PEP 804: An External Dependency Registry and Name Mapping Mechanism (Added)
• PEP 806: Mixed Sync/Async Context Managers With Precise Async Marking (Added)
• PEP 807: Index Support for Trusted Publishing (Added)
• PEP 809: Stable ABI for the Future (Added)
• PEP 810: Explicit Lazy Imports (Added)
• Python lazy imports you can use today - PythonTest
• Lazy Imports Using wrapt – PEP 810 proposes adding explicit lazy imports to Python, but you can already achieve this with third-party libraries. This post shows you how using wrapt.

Show Links:

• Python 3.14 Is Here. How Fast Is It? – A comprehensive deep-dive comparison of performance figures between Python versions and variations, including the JIT and free-threaded mode.
• Free-Threaded Python Library Compatibility Checker – A heat map and table summarizing Python free-threaded compatibility in a variety of common Python packages.
• Python 3.14: 3 asyncio Changes – asyncio changes are often overlooked. In the latest 3.14 release, there are three new asyncio features and changes.
• Scaling Asyncio on Free-Threaded Python – A recap of the work done in Python 3.14 to enable asyncio to scale on the free-threaded build of CPython.
• Intro to NiceGUI: Build Interactive Python Web Apps – Use NiceGUI to turn Python scripts into interactive web apps without touching HTML, CSS, or JavaScript.

Discussion:

• What Is “Good Taste” in Software Engineering? – This opinion piece discusses the difference between skill and taste when writing software. What counts as “clean code” for one person may not be the same for another.

Projects:

• Try Sphinx Docs Instantly in Your Browser
• Introducing tdom: HTML Templating With t‑strings – Python 3.14 introduces t-strings, and this article showcases tdom, a new HTML DOM toolkit that takes advantage of them to produce safer output.

Additional Links:

• Benchmarking MicroPython - miguelgrinberg.com
• Is Python Really That Slow? - miguelgrinberg.com
• Bubble sort - Wikipedia
• Fibonacci sequence - Wikipedia
• Python 3.14: Cool New Features for You to Try – Real Python
• What’s New in Python 3.14 – Real Python
• Python 3.14 Preview: REPL Autocompletion and Highlighting – Real Python
• Python 3.13 Preview: A Modern REPL – Real Python
• Python 3.14 Preview: Lazy Annotations – Real Python
• Python 3.14 Preview: Better Syntax Error Messages – Real Python
• Python 3.14 Preview: Template Strings (T-Strings) – Real Python
• Python 3.13: Free Threading and a JIT Compiler – Real Python
• Quasar Framework

Level up your Python skills with our expert-led courses:

• Building a Python GUI Application With Tkinter
• Documenting Python Projects With Sphinx and Read the Docs
• What's New in Python 3.14

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