Python Bytes

#457 Tapping into HTTP

Topics covered in this episode: httptap 10 Smart Performance Hacks For Faster Python Code FastRTC Explore Python dependencies with pipdeptree and uv pip tree Extras Joke Watch on YouTube About the show Sponsored by us! Support our work through: Our courses at Talk Python Training The Complete pytest Course Patreon Supporters Connect with the hosts Michael: @mkennedy@fosstodon.org / @mkennedy.codes (bsky) Brian: @brianokken@fosstodon.org / @brianokken.bsky.social Show: @pythonbytes@fosstodon.org / @pythonbytes.fm (bsky) Join us on YouTube at pythonbytes.fm/live to be part of the audience. Usually Monday at 10am PT. Older video versions available there too. Finally, if you want an artisanal, hand-crafted digest of every week of the show notes in email form? Add your name and email to our friends of the show list, we'll never share it. Michael #1: httptap Rich-powered CLI that breaks each HTTP request into DNS, connect, TLS, wait, and transfer phases with waterfall timelines, compact summaries, or metrics-only output. Features Phase-by-phase timing – precise measurements built from httpcore trace hooks (with sane fallbacks when metal-level data is unavailable). All HTTP methods – GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS with request body support. Request body support – send JSON, XML, or any data inline or from file with automatic Content-Type detection. IPv4/IPv6 aware – the resolver and TLS inspector report both the address and its family. TLS insights – certificate CN, expiry countdown, cipher suite, and protocol version are captured automatically. Multiple output modes – rich waterfall view, compact single-line summaries, or -metrics-only for scripting. JSON export – persist full step data (including redirect chains) for later processing. Extensible – clean Protocol interfaces for DNS, TLS, timing, visualization, and export so you can plug in custom behavior. Example: Brian #2: 10 Smart Performance Hacks For Faster Python Code Dido Grigorov A few from the list Use math functions instead of operators Avoid exception handling in hot loops Use itertools for combinatorial operations - huge speedup Use bisect for sorted list operations - huge speedup Michael #3: FastRTC The Real-Time Communication Library for Python: Turn any python function into a real-time audio and video stream over WebRTC or WebSockets. Features 🗣️ Automatic Voice Detection and Turn Taking built-in, only worry about the logic for responding to the user. 💻 Automatic UI - Use the .ui.launch() method to launch the webRTC-enabled built-in Gradio UI. 🔌 Automatic WebRTC Support - Use the .mount(app) method to mount the stream on a FastAPI app and get a webRTC endpoint for your own frontend! ⚡️ Websocket Support - Use the .mount(app) method to mount the stream on a FastAPI app and get a websocket endpoint for your own frontend! 📞 Automatic Telephone Support - Use the fastphone() method of the stream to launch the application and get a free temporary phone number! 🤖 Completely customizable backend - A Stream can easily be mounted on a FastAPI app so you can easily extend it to fit your production application. See the Talk To Claude demo for an example of how to serve a custom JS frontend. Brian #4: Explore Python dependencies with pipdeptree and uv pip tree Suggested by Nicholas Carsner We have covered it, but in 2017 on episode 17. pipdeptree Use pipdeptree --python auto to allow it to read your venv uv pip tree Also check out uv pip tree and some useful flags --show-version-specifiers to show the rules --outdated notes packages that need updated Extras Brian: Lean TDD 0.1.1 includes an updated intro and another chapter, “Essential Components” VSCode Peacock Extension - color code your different projects Joke: Sure Grandma

#456 You're so wrong

Topics covered in this episode: The PSF has withdrawn a $1.5 million proposal to US government grant program A Binary Serializer for Pydantic Models T-strings: Python's Fifth String Formatting Technique? Cronboard Extras Joke Watch on YouTube About the show Sponsored by us! Support our work through: Our courses at Talk Python Training The Complete pytest Course Patreon Supporters Connect with the hosts Michael: @mkennedy@fosstodon.org / @mkennedy.codes (bsky) Brian: @brianokken@fosstodon.org / @brianokken.bsky.social Show: @pythonbytes@fosstodon.org / @pythonbytes.fm (bsky) Join us on YouTube at pythonbytes.fm/live to be part of the audience. Usually Monday at 10am PT. Older video versions available there too. Finally, if you want an artisanal, hand-crafted digest of every week of the show notes in email form? Add your name and email to our friends of the show list, we'll never share it. Brian #1: The PSF has withdrawn a $1.5 million proposal to US government grant program Related post from Simon Willison ARS Technica: Python plan to boost software security foiled by Trump admin’s anti-DEI rules The Register: Python Foundation goes ride or DEI, rejects government grant with strings attached In Jan 2025, the PSF submitted a proposal for a US NSF grant under the Safety, Security, and Privacy of Open Source Ecosystems program. After months of work by the PSF, the proposal was recommended for funding. If the PSF accepted it, however, they would need to agree to the some terms and conditions, including, affirming that the PSF doesn't support diversity. The restriction wouldn't just be around the security work, but around all activity of the PSF as a whole. And further, that any deemed violation would give the NSF the right to ask for the money back. That just won't work, as the PSF would have already spent the money. The PSF mission statement includes "The mission of the Python Software Foundation is to promote, protect, and advance the Python programming language, and to support and facilitate the growth of a diverse and international community of Python programmers." The money would have obviously been very valuable, but the restrictions are just too unacceptable. The PSF withdrew the proposal. This couldn't have been an easy decision, that was a lot of money, but I think the PSF did the right thing. Michael #2: A Binary Serializer for Pydantic Models 7× Smaller Than JSON A compact binary serializer for Pydantic models that dramatically reduces RAM usage compared to JSON. The library is designed for high-load systems (e.g., Redis caching), where millions of models are stored in memory and every byte matters. It serializes Pydantic models into a minimal binary format and deserializes them back with zero extra metadata overhead. Target Audience: This project is intended for developers working with: high-load APIs in-memory caches (Redis, Memcached) message queues cost-sensitive environments where object size matters Brian #3: T-strings: Python's Fifth String Formatting Technique? Trey Hunner Python 3.14 has t-strings. How do they fit in with the rest of the string story? History percent-style (%) strings - been around for a very long time string.Template - and t.substitute() - from Python 2.4, but I don’t think I’ve ever used them bracket variables and .format() - Since Python 2.6 f-strings - Python 3.6 - Now I feel old. These still seem new to me t-strings - Python 3.14, but a totally different beast. These don’t return strings. Trey then covers a problem with f-strings in that the substitution happens at definition time. t-strings have substitution happen later. this is essentially “lazy string interpolation” This still takes a bit to get your head around, but I appreciate Trey taking a whack at the explanation. Michael #4: Cronboard Cronboard is a terminal application that allows you to manage and schedule cronjobs on local and remote servers. With Cronboard, you can easily add, edit, and delete cronjobs, as well as view their status. ✨ Features ✔️ Check cron jobs ✔️ Create cron jobs with validation and human-readable feedback ✔️ Pause and resume cron jobs ✔️ Edit existing cron jobs ✔️ Delete cron jobs ✔️ View formatted last and next run times ✔️ Accepts special expressions like @daily, @yearly, @monthly, etc. ✔️ Connect to servers using SSH, using password or SSH keys ✔️ Choose another user to manage cron jobs if you have the permissions to do so (sudo) Extras Brian: PEP 810: Explicit lazy imports, has been unanimously accepted by steering council Lean TDD book will be written in the open. TOC, some details, and a 10 page introduction are now available. Hoping for the first pass to be complete by the end of the year. I’d love feedback to help make it a great book, and keep it small-ish, on a very limited budget. Joke: You are so wrong!

#455 Gilded Python and Beyond

Topics covered in this episode: Cyclopts: A CLI library * The future of Python web services looks GIL-free* * Free-threaded GC* * Polite lazy imports for Python package maintainers* Extras Joke Watch on YouTube About the show Sponsored by us! Support our work through: Our courses at Talk Python Training The Complete pytest Course Patreon Supporters Connect with the hosts Michael: @mkennedy@fosstodon.org / @mkennedy.codes (bsky) Brian: @brianokken@fosstodon.org / @brianokken.bsky.social Show: @pythonbytes@fosstodon.org / @pythonbytes.fm (bsky) Join us on YouTube at pythonbytes.fm/live to be part of the audience. Usually Monday at 10am PT. Older video versions available there too. Finally, if you want an artisanal, hand-crafted digest of every week of the show notes in email form? Add your name and email to our friends of the show list, we'll never share it. Michael #1: Cyclopts: A CLI library A CLI library that fixes 13 annoying issues in Typer Much of Cyclopts was inspired by the excellent Typer library. Despite its popularity, Typer has some traits that I (and others) find less than ideal. Part of this stems from Typer's age, with its first release in late 2019, soon after Python 3.8's release. Because of this, most of its API was initially designed around assigning proxy default values to function parameters. This made the decorated command functions difficult to use outside of Typer. With the introduction of Annotated in python3.9, type-hints were able to be directly annotated, allowing for the removal of these proxy defaults. The 13: Argument vs Option Positional or Keyword Arguments Choices Default Command Docstring Parsing Decorator Parentheses Optional Lists Keyword Multiple Values Flag Negation Help Defaults Validation Union/Optional Support Adding a Version Flag Documentation Brian #2: The future of Python web services looks GIL-free Giovanni Barillari “Python 3.14 was released at the beginning of the month. This release was particularly interesting to me because of the improvements on the "free-threaded" variant of the interpreter. Specifically, the two major changes when compared to the free-threaded variant of Python 3.13 are: Free-threaded support now reached phase II, meaning it's no longer considered experimental The implementation is now completed, meaning that the workarounds introduced in Python 3.13 to make code sound without the GIL are now gone, and the free-threaded implementation now uses the adaptive interpreter as the GIL enabled variant. These facts, plus additional optimizations make the performance penalty now way better, moving from a 35% penalty to a 5-10% difference.” Lots of benchmark data, both ASGI and WSGI Lots of great thoughts in the “Final Thoughts” section, including “On asynchronous protocols like ASGI, despite the fact the concurrency model doesn't change that much – we shift from one event loop per process, to one event loop per thread – just the fact we no longer need to scale memory allocations just to use more CPU is a massive improvement. ” “… for everybody out there coding a web application in Python: simplifying the concurrency paradigms and the deployment process of such applications is a good thing.” “… to me the future of Python web services looks GIL-free.” Michael #3: Free-threaded GC The free-threaded build of Python uses a different garbage collector implementation than the default GIL-enabled build. The Default GC: In the standard CPython build, every object that supports garbage collection (like lists or dictionaries) is part of a per-interpreter, doubly-linked list. The list pointers are contained in a PyGC_Head structure. The Free-Threaded GC: Takes a different approach. It scraps the PyGC_Head structure and the linked list entirely. Instead, it allocates these objects from a special memory heap managed by the "mimalloc" library. This allows the GC to find and iterate over all collectible objects using mimalloc's data structures, without needing to link them together manually. The free-threaded GC does NOT support "generations” By marking all objects reachable from these known roots, we can identify a large set of objects that are definitely alive and exclude them from the more expensive cycle-finding part of the GC process. Overall speedup of the free-threaded GC collection is between 2 and 12 times faster than the 3.13 version. Brian #4: Polite lazy imports for Python package maintainers Will McGugan commented on a LI post by Bob Belderbos regarding lazy importing “I'm excited about this PEP. I wrote a lazy loading mechanism for Textual's widgets. Without it, the entire widget library would be imported even if you needed just one widget. Having this as a core language feature would make me very happy.” https://github.com/Textualize/textual/blob/main/src/textual/widgets/__init__.py Well, I was excited about Will’s example for how to, essentially, allow users of your package to import only the part they need, when they need it. So I wrote up my thoughts and an explainer for how this works. Special thanks to Trey Hunner’s Every dunder method in Python, which I referenced to understand the difference between __getattr__() and __getattribute__(). Extras Brian: Started writing a book on Test Driven Development. Should have an announcement in a week or so. I want to give folks access while I’m writing it, so I’ll be opening it up for early access as soon as I have 2-3 chapters ready to review. Sign up for the pythontest newsletter if you’d like to be informed right away when it’s ready. Or stay tuned here. Michael: New course!!! Agentic AI Programming for Python I’ll be on Vanishing Gradients as a guest talking book + ai for data scientists OpenAI launches ChatGPT Atlas https://github.com/jamesabel/ismain by James Abel Pets in PyCharm Joke: You're absolutely right

#454 It's some form of Elvish

Topics covered in this episode: * djrest2 -* A small and simple REST library for Django based on class-based views. Github CLI caniscrape - Know before you scrape. Analyze any website's anti-bot protections in seconds. * 🐴 GittyUp* Extras Joke Watch on YouTube About the show Sponsored by us! Support our work through: Our courses at Talk Python Training The Complete pytest Course Patreon Supporters Connect with the hosts Michael: @mkennedy@fosstodon.org / @mkennedy.codes (bsky) Brian: @brianokken@fosstodon.org / @brianokken.bsky.social Show: @pythonbytes@fosstodon.org / @pythonbytes.fm (bsky) Join us on YouTube at pythonbytes.fm/live to be part of the audience. Usually Monday at 10am PT. Older video versions available there too. Finally, if you want an artisanal, hand-crafted digest of every week of the show notes in email form? Add your name and email to our friends of the show list, we'll never share it. Brian #1: djrest2 - A small and simple REST library for Django based on class-based views. Emma Levit Based on an interesting blog post Why, in 2025, do we still need a 3rd party app to write a REST API with Django? As opposed to using DRF or Django Ninja - Michael #2: Github CLI GitHub’s official command line tool Features Checking out a pull request locally You can clone any repository using OWNER/REPO syntax: gh repo clone cli/cli Create a pull request interactively: gh pr create See all at cli.github.com/manual/examples Brian #3: caniscrape - Know before you scrape. Analyze any website's anti-bot protections in seconds. reddit announcement and discussion caniscrape checks a website for common anti-bot mechanisms and reports: A difficulty score (0–10) Which protections are active (e.g., Cloudflare, Akamai, hCaptcha, etc.) What tools you’ll likely need (headless browsers, proxies, CAPTCHA solvers, etc.) Whether using a scraping API might be better This helps you decide the right scraping approach before you waste time building a bot that keeps getting blocked. Michael #4: 🐴 GittyUp Never forget to pull again: Automatically discover and update all your Git repositories with one command. Built initially to solve this problem Rebuilt and published last week as part of my upcoming Agentic AI Programming for Python course. Get notified this week at training.talkpython.fm/getnotified Update everything in a folder tree with gittyup Review changes, blockers, etc with gittyup --explain Extras Brian: Three times faster with lazy imports - Hugo van Kemenade Interesting discussion on Hugo’s post - on Mastodon Use lazy module imports now - Graham Dumpleton Graham’s post uses wrapt, a “module for decorators, wrappers and monkey patching”, to simulate lazy imports Helpful comment from Adam Johnson on Graham’s post to actually do the import during type checking using if TYPE_CHECKING: import ... Michael: uvloop is back! pypi+ listened. :) https://www.reddit.com/r/Python/comments/1o9dey5/i_just_released_pypipluscom_20_offlineready/ Feedback from my “Show me your ls” post. Joke: Some form of Elvish

#453 Python++

Topics covered in this episode: * PyPI+* * uv-ship - a CLI-tool for shipping with uv* * How fast is 3.14?* * air - a new web framework built with FastAPI, Starlette, and Pydantic.* Extras Joke Watch on YouTube About the show Sponsored by us! Support our work through: Our courses at Talk Python Training The Complete pytest Course Patreon Supporters Connect with the hosts Michael: @mkennedy@fosstodon.org / @mkennedy.codes (bsky) Brian: @brianokken@fosstodon.org / @brianokken.bsky.social Show: @pythonbytes@fosstodon.org / @pythonbytes.fm (bsky) Join us on YouTube at pythonbytes.fm/live to be part of the audience. Usually Monday at 10am PT. Older video versions available there too. Finally, if you want an artisanal, hand-crafted digest of every week of the show notes in email form? Add your name and email to our friends of the show list, we'll never share it. Michael #1: PyPI+ Very nice search and exploration tool for PyPI Minor but annoying bug: content-types ≠ content_types on PyPI+ but they are in Python itself. Minimum Python version seems to be interpreted as max Python version. See dependency graphs and more Examples content-types jinja-partials fastapi-chameleon Brian #2: uv-ship - a CLI-tool for shipping with uv “uv-ship is a lightweight companion to uv that removes the risky parts of cutting a release. It verifies the repo state, bumps your project metadata and optionally refreshes the changelog. It then commits, tags & pushes the result, while giving you the chance to review every step.” Michael #3: How fast is 3.14? by Miguel Grinberg A big focus on threaded vs. non-threaded Python Some times its faster, other times, it’s slower Brian #4: air - a new web framework built with FastAPI, Starlette, and Pydantic. An very new project in Alpha stage by Daniel & Audrey Felderoy, the “Two Scoops of Django” people. Air Tags are an interesting thing. Also Why? is amazing “Don't use AIR” “Every release could break your code! If you have to ask why you should use it, it's probably not for you.” “If you want to use Air, you can. But we don't recommend it.” “It'll likely infect you, your family, and your codebase with an evil web framework mind virus, , …” Extras Brian: Python 3.15a1 is available uv python install 3.15 already works Python lazy imports you can use today - one of two blog posts I threatened to write recently Testing against Python 3.14 - the other one Free Threading has some trove classifiers Michael: Blog post about the book: Talk Python in Production book is out! In particular, the extras are interesting. AI Usage TUI Show me your ls Helium Browser is interesting. But also has Python as a big role. GitHub says Languages Python 97.4% 👀 Shell 1.9% Other 0.7% Smallest Python release? 3.13.9 Joke: An unforgivable crime