Python Bytes is a weekly podcast hosted by Michael Kennedy and Brian Okken. The show is a short discussion on the headlines and noteworthy news in the Python, developer, and data science space.
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#447 Going down a rat hole
Topics covered in this episode: * rathole* * pre-commit: install with uv* A good example of what functools.Placeholder from Python 3.14 allows Converted 160 old blog posts with AI Extras Joke Watch on YouTube About the show Sponsored by DigitalOcean: pythonbytes.fm/digitalocean-gen-ai Use code DO4BYTES and get $200 in free credit 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: rathole A lightweight and high-performance reverse proxy for NAT traversal, written in Rust. An alternative to frp and ngrok. Features High Performance Much higher throughput can be achieved than frp, and more stable when handling a large volume of connections. Low Resource Consumption Consumes much fewer memory than similar tools. See Benchmark. The binary can be as small as ~500KiB to fit the constraints of devices, like embedded devices as routers. On my server, it’s currently using about 2.7MB in Docker (wow!) Security Tokens of services are mandatory and service-wise. The server and clients are responsible for their own configs. With the optional Noise Protocol, encryption can be configured at ease. No need to create a self-signed certificate! TLS is also supported. Hot Reload Services can be added or removed dynamically by hot-reloading the configuration file. HTTP API is WIP. Brian #2: pre-commit: install with uv Adam Johnson pre-commit doesn’t natively support uv, but you can get around that with pre-commit-uv $ uv tool install pre-commit --with pre-commit-uv Installing pre-commit like this Installs it globally Installs with uv adds an extra plugin “pre-commit-uv” to pre-commit, so that any Python based tool installed via pre-commit also uses uv Very cool. Nice speedup Brian #3: A good example of what functools.Placeholder from Python 3.14 allows Rodrigo Girão Serrão Remove punctuation functionally Also How to use functools.Placeholder, a blog post about it. functools.partial is cool way to create a new function that partially binds some parameters to another function. It doesn’t always work for functions that take positional arguments. functools.Placeholder fixes that with the ability to put in placeholders for spots where you want to be able to pass that in from the outer partial binding. And all of this sounds totally obscure without a good example, so thank you to Rodgrigo for coming up with the punctuation removal example (and writeup) Michael #4: Converted 160 old blog posts with AI They were held-hostage at wordpress.com to markdown and integrated them into my Hugo site at mkennedy.codes Here is the chat conversation with Claude Opus/Sonnet. Had to juggle this a bit because the RSS feed only held the last 50. So we had to go back in and web scrape. That resulted in oddies like comments on wordpress that had to be cleaned etc. Whole process took 3-4 hours from idea to “production”duction”. The chat transcript is just the first round getting the RSS → Hugo done. The fixes occurred in other chats. This article is timely and noteworthy: Blogging service TypePad is shutting down and taking all blog content with it This highlights why your domain name needs to be legit, not just tied to the host. I’m looking at you pyfound.blogspot.com. I just redirected blog.michaelckennedy.net to mkennedy.codes Carefully mapping old posts to a new archived area using NGINX config. This is just the HTTP portion, but note the /sitemap.xml and location ~ "^/([0-9]{4})/([0-9]{2})/([0-9]{2})/(.+?)/?$" { portions. The latter maps posts such as https://blog.michaelckennedy.net/2018/01/08/a-bunch-of-online-python-courses/ to https://mkennedy.codes/posts/r/a-bunch-of-online-python-courses/ server { listen 80; server_name blog.michaelckennedy.net; # Redirect sitemap.xml to new domain location = /sitemap.xml { return 301 <https://mkennedy.codes/sitemap.xml>; } # Handle blog post redirects for HTTP -> HTTPS with URL transformation # Pattern: /YYYY/MM/DD/post-slug/ -> <https://mkennedy.codes/posts/r/post-slug/> location ~ "^/([0-9]{4})/([0-9]{2})/([0-9]{2})/(.+?)/?$" { return 301 <https://mkennedy.codes/posts/r/$4/>; } # Redirect all other HTTP URLs to mkennedy.codes homepage location / { return 301 <https://mkennedy.codes/>; } } Extras Brian: SMS URLs and Draft SMS and iMessage from any computer keyboard from Seth Larson Test and Code Archive is now up, see announcement Michael: Python: The Documentary | An origin story is out! Joke: Do you know him? He is me.
#446 State of Python 2025
Topics covered in this episode: * pypistats.org was down, is now back, and there’s a CLI* * State of Python 2025* * wrapt: A Python module for decorators, wrappers and monkey patching.* pysentry 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: pypistats.org was down, is now back, and there’s a CLI pypistats.org is a cool site to check the download stats for Python packages. It was down for a while, like 3 weeks? A couple days ago, Hugo van Kemenade announced that it was back up. With some changes in stewardship “pypistats.org is back online! 🚀📈 Thanks to @jezdez for suggesting the @ThePSF takes stewardship and connecting the right people, to @EWDurbin for migrating, and of course to Christopher Flynn for creating and running it for all these years!” Hugo has a CLI version, pypistats You can give it a command for what you want to search for recent,overall, python_major, python_minor, system Then either a package name, a directory path, or if nothing, it will grab the current directory package via pyproject.toml or setup.cfg very cool Michael #2: State of Python 2025 Michael’s Themes Python people use Python: 86% of respondents use Python as their main language We are mostly brand-new programmers: Exactly 50% of respondents have less than two years of professional coding experience Data science is now over half of all Python Most still use older Python versions despite benefits of newer releases: Compelling math to make the change. Python web devs resurgence Forward-looking trends Agentic AI will be wild Async, await, and threading are becoming core to Python Python GUIs and mobile are rising Actionable ideas Action 1: Learn uv Action 2: Use the latest Python Action 3: Learn agentic AI Action 4: Learn to read basic Rust Action 5: Invest in understanding threading Action 6: Remember the newbies Brian #3: wrapt: A Python module for decorators, wrappers and monkey patching. “The aim of the wrapt module is to provide a transparent object proxy for Python, which can be used as the basis for the construction of function wrappers and decorator functions. An easy to use decorator factory is provided to make it simple to create your own decorators that will behave correctly in any situation they may be used.” Why not just use functools.wraps()? “The wrapt module focuses very much on correctness. It therefore goes way beyond existing mechanisms such as functools.wraps() to ensure that decorators preserve introspectability, signatures, type checking abilities etc. The decorators that can be constructed using this module will work in far more scenarios than typical decorators and provide more predictable and consistent behaviour.” There’s a bunch of blog posts from 2014 / 2015 (and kept updated) that talk about how wrapt solves many issues with traditional ways to decorate and patch things in Python, including “How you implemented your Python decorator is wrong”. Docs are pretty good, with everything from simple wrappers to an example of building a wrapper to handle thread synchronization Michael #4: pysentry via Owen Lamont Install via uv tool install pysentry-rs Scan your Python dependencies for known security vulnerabilities with Rust-powered scanner. PySentry audits Python projects for known security vulnerabilities by analyzing dependency files (uv.lock, poetry.lock, Pipfile.lock, pyproject.toml, Pipfile, requirements.txt) and cross-referencing them against multiple vulnerability databases. It provides comprehensive reporting with support for various output formats and filtering options. Key Features: Multiple Project Formats: Supports uv.lock, poetry.lock, Pipfile.lock, pyproject.toml, Pipfile, and requirements.txt files External Resolver Integration: Leverages uv and pip-tools for accurate requirements.txt constraint solving Multiple Data Sources: PyPA Advisory Database (default) PyPI JSON API OSV.dev (Open Source Vulnerabilities) Flexible Output for different workflows: Human-readable, JSON, SARIF, and Markdown formats Performance Focused: Written in Rust for speed Async/concurrent processing Multi-tier intelligent caching (vulnerability data + resolved dependencies) Comprehensive Filtering: Severity levels (low, medium, high, critical) Dependency scopes (main only vs all [optional, dev, prod, etc] dependencies) Direct vs. transitive dependencies Enterprise Ready: SARIF output for IDE/CI integration I tried it on pythonbytes.fm and found only one issue, sadly can’t be fixed: PYSENTRY SECURITY AUDIT ======================= SUMMARY: 89 packages scanned • 1 vulnerable • 1 vulnerabilities found SEVERITY: 1 LOW UNFIXABLE: 1 vulnerabilities cannot be fixed VULNERABILITIES --------------- 1. PYSEC-2022-43059 aiohttp v3.12.15 [LOW] [source: pypa-zip] AIOHTTP 3.8.1 can report a "ValueError: Invalid IPv6 URL" outcome, which can lead to a Denial of Service (DoS). NOTE:... Scan completed Extras Michael: I’ve been rumbling with rumdl. Ruben fixed one of my complaints about it with issue #58. Config seems like it might be off. Here’s mine .rumdl.toml. I’ve been using it on the upcoming Talk Python in Production book Read the first third online and get notified when its out. 20 or so Markdown files 45,000 words of content I asked if 3.13.6 would be the last 3.13 release? No. Thanks Hugo. Python 3.13.7 is now out. Joke: Marked for destruction
#445 Auto-activate Python virtual environments for any project
Topics covered in this episode: pyx - optimized backend for uv * Litestar is worth a look* * Django remake migrations* * django-chronos* Extras Joke Watch on YouTube About the show Python Bytes 445 Sponsored by Sentry: pythonbytes.fm/sentry - Python Error and Performance Monitoring 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: pyx - optimized backend for uv via John Hagen (thanks again) I’ll be interviewing Charlie in 9 days on Talk Python → Sign up (get notified) of the livestream here. Not a PyPI replacement, more of a middleware layer to make it better, faster, stronger. pyx is a paid service, with maybe a free option eventually. Brian #2: Litestar is worth a look James Bennett Michael brought up Litestar in episode 444 when talking about rewriting TalkPython in Quart James brings up scaling - Litestar is easy to split an app into multiple files Not using pydantic - You can use pydantic with Litestar, but you don’t have to. Maybe attrs is right for you instead. Michael brought up Litestar seems like a “more batteries included” option. Somewhere between FastAPI and Django. Brian #3: Django remake migrations Suggested by Bruno Alla on BlueSky In response to a migrations topic last week django-remake-migrations is a tool to help you with migrations and the docs do a great job of describing the problem way better than I did last week “The built-in squashmigrations command is great, but it only work on a single app at a time, which means that you need to run it for each app in your project. On a project with enough cross-apps dependencies, it can be tricky to run.” “This command aims at solving this problem, by recreating all the migration files in the whole project, from scratch, and mark them as applied by using the replaces attribute.” Also of note The package was created with Copier Michael brought up Copier in 2021 in episode 219 It has a nice comparison table with CookieCutter and Yoeman One difference from CookieCutter is yml vs json. I’m actually not a huge fan of handwriting either. But I guess I’d rather hand write yml. So I’m thinking of trying Copier with my future project template needs. Michael #4: django-chronos Django middleware that shows you how fast your pages load, right in your browser. Displays request timing and query counts for your views and middleware. Times middleware, view, and total per request (CPU and DB). Extras Brian: Test & Code 238: So Long, and Thanks for All the Fish after 10 years, this is the goodbye episode Michael: Auto-activate Python virtual environment for any project with a venv directory in your shell (macOS/Linux): See gist. Python 3.13.6 is out. Open weight OpenAI models Just Enough Python for Data Scientists Course The State of Python 2025 article by Michael Joke: python is better than java
#444 Begone Python of Yore!
Topics covered in this episode: Coverage.py regex pragmas * Python of Yore* * nox-uv* * A couple Django items* Extras Joke Watch on YouTube About the show Sponsored by DigitalOcean: pythonbytes.fm/digitalocean-gen-ai Use code DO4BYTES and get $200 in free credit Connect with the hosts Michael: @mkennedy@fosstodon.org / @mkennedy.codes (bsky) Brian: @brianokken@fosstodon.org / @brianokken.bsky.social Show: @pythonbytes@fosstodon.org / @pythonbytes.fm (bsky) Join us on YouTube at pythonbytes.fm/live to be part of the audience. Usually Monday at 10am PT. Older video versions available there too. Finally, if you want an artisanal, hand-crafted digest of every week of the show notes in email form? Add your name and email to our friends of the show list, we'll never share it. Brian #1: Coverage.py regex pragmas Ned Batchelder The regex implementation of how coverage.py recognizes pragmas is pretty amazing. It’s extensible through plugins covdefaults adds a bunch of default exclusions, and also platform- and version-specific comment syntaxes. coverage-conditional-plugin gives you a way to create comment syntaxes for entire files, for whether other packages are installed, and so on. A change from last year (as part of coverage.py 7.6 allows multiline regexes, which let’s us do things like: Exclude an entire file with \\A(?s:.*# pragma: exclude file.*)\\Z Allow start and stop delimiters with # no cover: start(?s:.*?)# no cover: stop Exclude empty placeholder methods with ^\\s*(((async )?def .*?)?\\)(\\s*->.*?)?:\\s*)?\\.\\.\\.\\s*(#|$) See Ned’s article for explanations of these Michael #2: Python of Yore via Matthias Use YORE: ... comments to highlight CPython version dependencies. # YORE: EOL 3.8: Replace block with line 4. if sys.version_info < (3, 9): from astunparse import unparse else: from ast import unparse Then check when they go out of support: $ yore check --eol-within '5 months' ./src/griffe/agents/nodes/_values.py:11: Python 3.8 will reach its End of Life within approx. 4 months Even fix them with fix . Michael #3: nox-uv via John Hagen What nox-uv does is make it very simple to install uv extras and/or dependency groups into a nox session's virtual environment. The versions installed are constrained by uv's lockfile meaning that everything is deterministic and pinned. Dependency groups make it very easy to install only want is necessary for a session (e.g., only linting dependencies like Ruff, or main dependencies + mypy for type checking). Brian #4: A couple Django items Stop Using Django's squashmigrations: There's a Better Way Johnny Metz Resetting migrations is sometimes the right thing. Overly simplified summary: delete migrations and start over dj-lite Adam Hill Use SQLite in production with Django “Simplify deploying and maintaining production Django websites by using SQLite in production. dj-lite helps enable the best performance for SQLite for small to medium-sized projects. It requires Django 5.1+.” Extras Brian: Test & Code 237: FastAPI Cloud with Sebastian Ramirez will be out later today pythontest.com: pytest fixtures nuts and bolts - revisited A blog series that I wrote a long time ago. I’ve updated it into more managable bite-sized pieces, updated and tested with Python 3.13 and pytest 8 Michael: New course: Just Enough Python for Data Scientists My live stream about uv is now on YouTube Cursor CLI: Built to help you ship, right from your terminal. Joke: Copy/Paste
#443 Patching Multiprocessing
Topics covered in this episode: rumdl - A Markdown Linter written in Rust * Coverage 7.10.0: patch* * aioboto3* * You might not need a Python class* Extras Joke Watch on YouTube About the show 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: rumdl - A Markdown Linter written in Rust via Owen Lamont Supports toml file config settings Install via uv tool install rumdl. ⚡️ Built for speed with Rust - significantly faster than alternatives 🔍 54 lint rules covering common Markdown issues 🛠️ Automatic fixing with -fix for most rules 📦 Zero dependencies - single binary with no runtime requirements 🔧 Highly configurable with TOML-based config files 🌐 Multiple installation options - Rust, Python, standalone binaries 🐍 Installable via pip for Python users 📏 Modern CLI with detailed error reporting 🔄 CI/CD friendly with non-zero exit code on errors Brian #2: Coverage 7.10.0: patch Ned Batchelder Actually up to 7.10.2 as of today patch allows coverage to run better when a covered project uses subprocesses os._exit() execv family of functions Looking at subprocess “Coverage works great when you start your program with coverage measurement, but has long had the problem of how to also measure the coverage of sub-processes that your program created. The existing solution had been a complicated two-step process of creating obscure .pth files and setting environment variables. Whole projects appeared on PyPI to handle this for you.” From release notes for 7.10.0 A new configuration option: “[run] patch” specifies named patches to work around some limitations in coverage measurement. These patches are available: patch = _exit lets coverage save its data even when <code>os._exit()</code> is used to abruptly end the process. This closes long-standing issue 310 as well as its duplicates: issue 312, issue 1673, issue 1845, and issue 1941. patch = subprocess measures coverage in Python subprocesses created with <code>subprocess</code>, <code>os.system()</code>, or one of the <code>execv</code> or <code>spawnv</code> family of functions. Closes old issue 367 and duplicate issue 378. patch = execv adjusts the <code>execv</code> family of functions to save coverage data before ending the current program and starting the next. Not available on Windows. Closes issue 43 after 15 years! Michael #3: aioboto3 via Pat Decker Wrapper to use boto3 resources with the aiobotocore async backend aiobotocore allows you to use near enough all of the boto3 client commands in an async manner just by prefixing the command with await. With aioboto3 you can now use the higher level APIs provided by boto3 in an asynchronous manner. Brian #4: You might not need a Python class Adam Grant This is an important periodic reminder to everyone coming into Python from other languages. Many other languages lean on classes a lot more than we need to in Python Adams suggestions Simple Data Containers: Use Named Tuples or Data Classes Stateless Utility Functions: Just Use Functions Grouping Constants: Use Modules Managing State with Simple Structures: Use Dictionaries or Lists Simple One-off Operations: Use Lambdas or Comprehensions I’ll add “just use functions” Avoiding Complexity: Built-in Libraries When You Actually Need a Class I’ll add You probably don’t If you think you do, ask a friend. Friends don’t let friends create extraneous classes in Python. If you think your case is an exception, it probably isn’t If you think dataclasses aren’t right for you, check out attrs Extras Brian: PyPI Incident Report: Phishing Attack -Sent in by listener John Hagen Both of Adam Johnson’s recent-ish interviews are now up on Test & Code 236: Git Tips for Testing - Adam Johnson 235: pytest-django - Adam Johnson Michael: Dive into uv webcast with me and Will Vincent Joke: Default text editor
#442 Cloud bills in scientific notation
Topics covered in this episode: * Open Source Security work isn't “Special”* * uv v0.8* * Extra, Extra, Extra* Announcing Toad - a universal UI for agentic coding in the terminal 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: Open Source Security work isn't “Special” Seth Larson It seems like security is special in a sense that we don’t want just anyone working on the security aspect of a project. We just want the trusted maintainers, right? Seth is arguing that this is the wrong mindset It makes more sense that we maybe have security experts contribute to many projects, and that someone working on security for just one project doesn’t benefit from scale. “Maintainers don’t see how other projects are triaging vulnerabilities and can’t learn from each other. They can’t compare notes on what they are seeing and whether they are doing the right thing. Isolation in security work breeds a culture of fear. Fear of doing the wrong thing and making your users unsafe.” “These “security contributors” could be maintainers or contributors of other open source projects that know about security, they could be foundations offering up resources to their ecosystem, or engineers at companies helping their dependency graph.” But how do we build trust in these individuals? Meeting in person works. But there are other ways as well. I’d personally love to have someone contact me about a project of mine regarding a security problem or process that the project could/should follow. Especially if I could see other projects I trust already trusting this individual to work on the other projects. Michael #2: uv v0.8 Changes Install Python executables into a directory on the PATH Register Python versions with the Windows Registry Prompt before removing an existing directory in uv venv Bump --python-platform linux to manylinux_2_28 Make uv_build the default build backend in uv init And many more And uv v0.8.1 Lots of enhancements. And uv v0.8.2 And uv v0.8.3 Adds Add CPython 3.14.0rc1 Brian #3: Extra, Extra, Extra fstrings.wtf - Armin Ronacher Python 3.14 release candidate 1 is go! Django turns 20, with parties mkdocs-redirects I’m Tired of Talking About AI - Paddy Carver Michael #4: Announcing Toad - a universal UI for agentic coding in the terminal by Will McGugan A universal front-end for AI in the terminal. Watch the video. Joke: Heaviest objects in the universe And … Cloud Architects 2025 “They send us our cloud bills in scientific notation… “ 🙂
#441 It's Michaels All the Way Down
Topics covered in this episode: * Distributed sqlite follow up: Turso and Litestream* * PEP 792 – Project status markers in the simple index* Run coverage on tests docker2exe: Convert a Docker image to an executable Extras Joke Watch on YouTube About the show Sponsored by Digital Ocean: pythonbytes.fm/digitalocean-gen-ai Use code DO4BYTES and get $200 in free credit 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: Distributed sqlite follow up: Turso and Litestream Michael Booth: Turso marries the familiarity and simplicity of SQLite with modern, scalable, and distributed features. Seems to me that Turso is to SQLite what MotherDuck is to DuckDB. Mike Fiedler Continue to use the SQLite you love and care about (even the one inside Python runtime) and launch a daemon that watches the db for changes and replicates changes to an S3-type object store. Deeper dive: Litestream: Revamped Brian #2: PEP 792 – Project status markers in the simple index Currently 3 status markers for packages Trove Classifier status Indices can be yanked PyPI projects - admins can quarantine a project, owners can archive a project Proposal is to have something that can have only one state active archived quarantined deprecated This has been Approved, but not Implemented yet. Brian #3: Run coverage on tests Hugo van Kemenade And apparently, run Ruff with at least F811 turned on Helps with copy/paste/modify mistakes, but also subtler bugs like consumed generators being reused. Michael #4: docker2exe: Convert a Docker image to an executable This tool can be used to convert a Docker image to an executable that you can send to your friends. Build with a simple command: $ docker2exe --name alpine --image alpine:3.9 Requires docker on the client device Probably doesn’t map volumes/ports/etc, though could potentially be exposed in the dockerfile. Extras Brian: Back catalog of Test & Code is now on YouTube under @TestAndCodePodcast So far 106 of 234 episodes are up. The rest are going up according to daily limits. Ordering is rather chaotic, according to upload time, not release ordering. There will be a new episode this week pytest-django with Adam Johnson Joke: If programmers were doctors
#440 Can't Register for VibeCon
Topics covered in this episode: * Switching to direnv, Starship, and uv* * rqlite - Distributed SQLite DB* * Some Markdown Stuff* Extras Joke Watch on YouTube About the show Sponsored by PropelAuth: pythonbytes.fm/propelauth77 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: Switching to direnv, Starship, and uv Last week I mentioned that I’m ready to try direnv again, but secretly, I still had some worries about the process. Thankfully, Trey has a tutorial to walk me past the troublesome parts. direnv - an extension for your shell. It augments existing shells with a new feature that can load and unload environment variables depending on the current directory. Switching from virtualenvwrapper to direnv, Starship, and uv - Trey Hunner** Trey has solved a bunch of the problems I had when I tried direnv before Show the virtual environment name in the prompt Place new virtual environments in local .venv instead of in .direnv/python3.12 Silence all of the “loading”, “unloading” statements every time you enter a directory Have a script called venv to create an environment, activate it, create a .envrc file I’m more used to a create script, so I’ll stick with that name and Trey’s contents A workon script to be able to switch around to different projects. This is a carry over from “virtualenvwrapper’, but seems cool. I’ll take it. Adding uv to the mix for creating virtual environments. Interestingly including --seed which, for one, installs pip in the new environment. (Some tools need it, even if you don’t) Starship Trey also has some setup for Starship. But I’ll get through the above first, then MAYBE try Starship again. Some motivation Trey’s setup is pretty simple. Maybe I was trying to get too fancy before Starship config in toml files that can be loaded with direnv and be different for different projects. Neato Also, Trey mentions his dotfiles repo. This is a cool idea that I’ve been meaning to do for a long time. See also: It's Terminal - Bootstrapping With Starship, Just, Direnv, and UV - Mario Munoz Michael #2: rqlite - Distributed SQLite DB via themlu, thanks! rqlite is a lightweight, user-friendly, distributed relational database built on SQLite. Built on SQLite, the world’s most popular database Supports full-text search, Vector Search, and JSON documents Access controls and encryption for secure deployments Michael #3: A Python dict that can report which keys you did not use by Peter Bengtsson Very cool for testing that a dictionary has been used as expected (e.g. all data has been sent out via an API or report). Note: It does NOT track d.get(), but it’s easy to just add it to the class in the post. Maybe someone should polish it up and put it on pypi (that person is not me :) ). Brian #4: Some Markdown Stuff Textual 4.0.0 adds Markdown.append which can be used to efficiently stream markdown content The reason for the major bump is due to an interface change to Widget.anchor Refreshing to see a symantic change cause a major version bump. html-to-markdown Converts html to markdown A complete rewrite fork of markdownify Lots of fun features like “streaming support” Curious if it can stream to Textual’s Markdown.append method. hmmm. Joke: Vibecon is hard to attend
#439 That Astral Episode
Topics covered in this episode: * ty documentation site and uv migration guide* * uv build backend is now stable + other Astral news* * Refactoring long boolean expressions* * fastapi-ml-skeleton* Extras Joke Watch on YouTube About the show Sponsored by Sentry: pythonbytes.fm/sentry 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: ty documentation site and uv migration guide via Skyler Kasko Astral created a documentation site for ty (PR #744 in release 0.0.1-alpha.13). Astral added a page on migrating from pip to a uv project in the uv documentation. (PR #12382 in release 0.7.19). Talk Python episode on ty. Brian #2: uv build backend is now stable + other Astral news The uv build backend is now stable Tim Hopper via Python Developer Tooling Handbook From Charlie Marsh “The uv build backend is now stable, and considered ready for production use. An alternative to setuptools, hatchling, etc. for pure Python projects, with a focus on good defaults, user-friendly error messages, and performance. When used with uv, it's 10-35x faster.” “(In a future release, we'll make this the default.)” [build-system] requires = ["uv_build>=0.7.19,<0.8.0"] build-backend = "uv_build" I believe it’s faster, but I agree with Brett Cannon in asking “What's being benchmarked? I'm not sure what a "backend sync" is referring to other than maybe installing the build back-end?” See also: uv: Making Python Local Workflows FAST and BORING in 2025 - Hynek Brian #3: Refactoring long boolean expressions Trey Hunner This is applied boolean logic, and even folks who learned this in a CS program probably did so early on, and may have forgotten it. How can you improve the readability of long Boolean expressions in Python? Put parens around the whole expression and separate clauses onto different lines Where to put boolean operators between clauses? at the end of the line or the beginning? PEP8 recommends the beginning if (expression1 and expression2 and expression3): ... Naming sub-expressions with variables Odd downside that wouldn’t occur to me. All expressions are evaluated, thus not taking advantage of expression short-circuiting. Naming operations with functions Less readable, but takes advantage of short-circuiting Using De Morgan’s Law : replacing a compound expression with a similar (and hopefully easier to read) expression # neither: we want both to be false not (a or b) == (not a) and (not b) # never_both: at least one false not (a and b) == (not a) or (not b) Michael #4: fastapi-ml-skeleton FastAPI Skeleton App to serve machine learning models production-ready. This repository contains a skeleton app which can be used to speed-up your next machine learning project. The code is fully tested and provides a preconfigured tox to quickly expand this sample code. A sample regression model for house price prediction is included in this project. Short write up on "What does set -a do?" Extras Brian: OCF Michael: via Wei Lee Extra Airflow ruff rules: Starting from Ruff version 0.11.13, most changes from Airflow 2 to Airflow 3 can be automated using AIR3. (It’s still in preview so a “—-preview” flag is needed) e.g., if you have the following Airflow 2 code import datetime from airflow.models import DAG from airflow.operators.empty import EmptyOperator with DAG( dag_id="my_dag_name", start_date=datetime.datetime(2021, 1, 1), schedule_interval="@daily", ): EmptyOperator(task_id="task") it can be fixed with uvx ruff check --select AIR3 --fix --unsafe-fixes --preview import datetime from airflow.sdk import DAG from airflow.providers.standard.operators.empty import EmptyOperator with DAG( dag_id="my_dag_name", start_date=datetime.datetime(2021, 1, 1), schedule="@daily", ): EmptyOperator(task_id="task") which works with Airflow 3. Joke: Front Toward Enemy
#438 Motivation time
Topics covered in this episode: * Python Cheat Sheets from Trey Hunner* * Automatisch* * mureq-typed* * My CLI World* Extras Joke Watch on YouTube About the show Sponsored by Posit: pythonbytes.fm/connect 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: Python Cheat Sheets from Trey Hunner Some fun sheets Python f-string tips & cheat sheets Python's pathlib module Python's many command-line utilities Michael #2: Automatisch Open source Zapier alternative Automatisch helps you to automate your business processes without coding. Use their affordable cloud solution or self-host on your own servers. Automatisch allows you to store your data on your own servers, good for companies dealing with sensitive user data, particularly in industries like healthcare and finance, or those based in Europe bound by General Data Protection Regulation (GDPR). Michael #3: mureq-typed Single file, zero-dependency alternative to requests. Fully typed. Modern Python tooling. Typed version of mureq (covered in 2022 on episode 268) Intended to be vendored in-tree by Linux systems software and other lightweight applications. mureq-typed is a drop-in, fully API compatible replacement for mureq updated with modern Python tooling: Type checked with mypy, ty, and pyrefly. Formatted with black, no ignore rules necessary. Linted with ruff (add these rules for mureq.py to your per-file-ignores). Brian #4: My CLI World Frank Wiles Encouragement to modify your command line environment Some of Franks tools direnv, zoxide, fd, ack, atuin, just Also some aliases, like gitpulllog Notes We covered poethepoet recently, if just just isn’t cutting it for you. I tried to ilke starship, bit for some reason with my setup, it slows down the shell too much. Extras Brian: Interesting read of the week: New theory proposes time has three dimensions, with space as a secondary effect Michael's: New quantum theory of gravity brings long-sought 'theory of everything' a crucial step closer Joke: Brian read a few quotes from the book Disappointing Affirmations, by Dave Tarnowski “You are always just a moment away from your next worst day ever. Or your next best day ever, but let’s be realistic.” “You can be anything you want. And yet you keep choosing to be you. I admire your dedication to the role.” “Today I am letting go of the things that are holding me back from the life that I want to live. Then I’m picking them all up again because I have separation anxiety.”
#437 Python Language Summit 2025 Highlights
Topics covered in this episode: * The Python Language Summit 2025* Fixing Python Properties * complexipy* * juvio* Extras Joke Watch on YouTube About the show Sponsored by Posit: pythonbytes.fm/connect 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: The Python Language Summit 2025 Write up by Seth Michael Larson How can we make breaking changes less painful?: talk by Itamar Oren An Uncontentious Talk about Contention: talk by Mark Shannon State of Free-Threaded Python: talk by Matt Page Fearless Concurrency: talk by Matthew Parkinson, Tobias Wrigstad, and Fridtjof Stoldt Challenges of the Steering Council: talk by Eric Snow Updates from the Python Docs Editorial Board: talk by Mariatta PEP 772 - Packaging Governance Process: talk by Barry Warsaw and Pradyun Gedam Python on Mobile - Next Steps: talk by Russell Keith-Magee What do Python core developers want from Rust?: talk by David Hewitt Upstreaming the Pyodide JS FFI: talk by Hood Chatham Lightning Talks: talks by Martin DeMello, Mark Shannon, Noah Kim, Gregory Smith, Guido van Rossum, Pablo Galindo Salgado, and Lysandros Nikolaou Brian #2: Fixing Python Properties Will McGugan “Python properties work well with type checkers such Mypy and friends. … The type of your property is taken from the getter only. Even if your setter accepts different types, the type checker will complain on assignment.” Will describes a way to get around this and make type checkers happy. He replaces @property with a descriptor. It’s a cool technique. I also like the way Will is allowing different ways to use a property such that it’s more convenient for the user. This is a cool deverloper usability trick. Brian #3: complexipy Calculates the cognitive complexity of Python files, written in Rust. Based on the cognitive complexity measurement described in a white paper by Sonar Cognitive complexity builds on the idea of cyclomatic complexity. Cyclomatic complexity was intended to measure the “testability and maintainability” of the control flow of a module. Sonar argues that it’s fine for testability, but doesn’t do well with measuring the “maintainability” part. So they came up with a new measure. Cognitive complexity is intended to reflects the relative difficulty of understanding, and therefore of maintaining methods, classes, and applications. complexipy essentially does that, but also has a really nice color output. Note: at the very least, you should be using “cyclomatic complexity” try with ruff check --select C901 But also try complexipy. Great for understanding which functions might be ripe for refactoring, adding more documentation, surrounding with more tests, etc. Michael #4: juvio uv kernel for Jupyter ⚙️ Automatic Environment Setup: When the notebook is opened, Juvio installs the dependencies automatically in an ephemeral virtual environment (using uv), ensuring that the notebook runs with the correct versions of the packages and Python 📁 Git-Friendly Format: Notebooks are converted on the fly to a script-style format using # %% markers, making diffs and version control painless Why Use Juvio? No additional lock or requirements files are needed Guaranteed reproducibility Cleaner Git diffs Powered By uv – ultra-fast Python package management PEP 723 – Python inline dependency standards Extras Brian: Test & Code in slow mode currently. But will be back with some awesome interviews. Joke: The 0.1x Engineer via Balázs Also StormTrooper vlog BIGFOOT VLOG - ATTACKED BY WENDIGO!
#436 Slow tests go last
Topics covered in this episode: * Free-threaded Python no longer “experimental” as of Python 3.14* typed-ffmpeg pyleak * Optimizing Test Execution: Running live_server Tests Last with pytest* Extras Joke Watch on YouTube About the show Sponsored by PropelAuth: pythonbytes.fm/propelauth66 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: Free-threaded Python no longer “experimental” as of Python 3.14 “PEP 779 ("Criteria for supported status for free-threaded Python") has been accepted, which means free-threaded Python is now a supported build!” - Hugo van Kemenade PEP 779 – Criteria for supported status for free-threaded Python As noted in the discussion of PEP 779, “The Steering Council (SC) approves PEP 779, with the effect of removing the “experimental” tag from the free-threaded build of Python 3.14.” We are in Phase II then. “We are confident that the project is on the right path, and we appreciate the continued dedication from everyone working to make free-threading ready for broader adoption across the Python community.” “Keep in mind that any decision to transition to Phase III, with free-threading as the default or sole build of Python is still undecided, and dependent on many factors both within CPython itself and the community. We leave that decision for the future.” How long will all this take? According to Thomas Wouters, a few years, at least: “In other words: it'll be a few years at least. It can't happen before 3.16 (because we won't have Stable ABI support until 15) and may well take longer.” Michael #2: typed-ffmpeg typed-ffmpeg offers a modern, Pythonic interface to FFmpeg, providing extensive support for complex filters with detailed typing and documentation. Inspired by ffmpeg-python, this package enhances functionality by addressing common limitations, such as lack of IDE integration and comprehensive typing, while also introducing new features like JSON serialization of filter graphs and automatic FFmpeg validation. Features : Zero Dependencies: Built purely with the Python standard library, ensuring maximum compatibility and security. User-Friendly: Simplifies the construction of filter graphs with an intuitive Pythonic interface. Comprehensive FFmpeg Filter Support: Out-of-the-box support for most FFmpeg filters, with IDE auto-completion. Integrated Documentation: In-line docstrings provide immediate reference for filter usage, reducing the need to consult external documentation. Robust Typing: Offers static and dynamic type checking, enhancing code reliability and development experience. Filter Graph Serialization: Enables saving and reloading of filter graphs in JSON format for ease of use and repeatability. Graph Visualization: Leverages graphviz for visual representation, aiding in understanding and debugging. Validation and Auto-correction: Assists in identifying and fixing errors within filter graphs. Input and Output Options Support: Provide a more comprehensive interface for input and output options, including support for additional codecs and formats. Partial Evaluation: Enhance the flexibility of filter graphs by enabling partial evaluation, allowing for modular construction and reuse. Media File Analysis: Built-in support for analyzing media files using FFmpeg's ffprobe utility, providing detailed metadata extraction with both dictionary and dataclass interfaces. Michael #3: pyleak Detect leaked asyncio tasks, threads, and event loop blocking with stack trace in Python. Inspired by goleak. Use as context managers or function dectorators When using no_task_leaks, you get detailed stack trace information showing exactly where leaked tasks are executing and where they were created. Even has great examples and a pytest plugin. Brian #4: Optimizing Test Execution: Running live_server Tests Last with pytest Tim Kamanin “When working with Django applications, it's common to have a mix of fast unit tests and slower end-to-end (E2E) tests that use pytest's live_server fixture and browser automation tools like Playwright or Selenium. ” Tim is running E2E tests last for Faster feedback from quick tests To not tie up resources early in the test suite. He did this with custom “e2e” marker Implementing a pytest_collection_modifyitems hook function to look for tests using the live_server fixture, and for them automatically add the e2e marker to those tests move those tests to the end The reason for the marker is to be able to Just run e2e tests with -m e2e Avoid running them sometimes with -m "not e2e" Cool small writeup. The technique works for any system that has some tests that are slower or resource bound based on a particular fixture or set of fixtures. Extras Brian: Is Free-Threading Our Only Option? - Interesting discussion started by Eric Snow and recommended by John Hagen Free-threaded Python on GitHub Actions - How to add FT tests to your projects, by Hugo van Kemenade Michael: New course! LLM Building Blocks in Python Talk Python Deep Dives Complete: 600K Words of Talk Python Insights .folders on Linux Write up on XDG for Python devs. They keep pulling me back - ChatGPT Pro with o3-pro Python Bytes is the #1 Python news podcast and #17 of all tech news podcasts. Python 3.13.4, 3.12.11, 3.11.13, 3.10.18 and 3.9.23 are now available Python 3.13.5 is now available! Joke: Naming is hard
#435 Stop with .folders in my ~/
Topics covered in this episode: platformdirs poethepoet - “Poe the Poet is a batteries included task runner that works well with poetry or with uv.” Python Pandas Ditches NumPy for Speedier PyArrow pointblank: Data validation made beautiful and powerful 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: platformdirs A small Python module for determining appropriate platform-specific dirs, e.g. a "user data dir". Why the community moved on from appdirs to platformdirs At AppDirs: Note: This project has been officially deprecated. You may want to check out pypi.org/project/platformdirs/ which is a more active fork of appdirs. Thanks to everyone who has used appdirs. Shout out to ActiveState for the time they gave their employees to work on this over the years. Better than AppDirs: Works today, works tomorrow – new Python releases sometimes change low-level APIs (win32com, pathlib, Apple sandbox rules). platformdirs tracks those changes so your code keeps running. First-class typing – no more types-appdirs stubs; editors autocomplete paths as Path objects. Richer directory set – if you need a user’s Downloads folder or a per-session runtime dir, there’s a helper for it. Cleaner internals – rewritten to use pathlib, caching, and extensive test coverage; all platforms are exercised in CI. Community stewardship – the project lives in the PyPA orbit and gets security/compatibility patches quickly. Brian #2: poethepoet - “Poe the Poet is a batteries included task runner that works well with poetry or with uv.” from Bob Belderbos Tasks are easy to define and are defined in pyproject.toml Michael #3: Python Pandas Ditches NumPy for Speedier PyArrow Pandas 3.0 will significantly boost performance by replacing NumPy with PyArrow as its default engine, enabling faster loading and reading of columnar data. Recently talked with Reuven Lerner about this on Talk Python too. In the next version, v3.0, PyArrow will be a required dependency, with pyarrow.string being the default type inferred for string data. PyArrow is 10 times faster. PyArrow offers columnar storage, which eliminates all that computational back and forth that comes with NumPy. PyArrow paves the way for running Pandas, by default, on Copy on Write mode, which improves memory and performance usage. Brian #4: pointblank: Data validation made beautiful and powerful “With its … chainable API, you can … validate your data against comprehensive quality checks …” Extras Brian: Ruff rules Ruff users, what rules are using and what are you ignoring? Python 3.14.0b2 - did we already cover this? Transferring your Mastodon account to another server, in case anyone was thinking about doing that I’m trying out Fathom Analytics for privacy friendly analytics Michael: Polars for Power Users: Transform Your Data Analysis Game Course Joke: Does your dog bite?
#434 Most of OpenAI’s tech stack runs on Python
Topics covered in this episode: Making PyPI’s test suite 81% faster People aren’t talking enough about how most of OpenAI’s tech stack runs on Python PyCon Talks on YouTube Optimizing Python Import Performance Extras Joke Watch on YouTube About the show Sponsored by Digital Ocean: pythonbytes.fm/digitalocean-gen-ai Use code DO4BYTES and get $200 in free credit 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: Making PyPI’s test suite 81% faster Alexis Challande The PyPI backend is a project called Warehouse It’s tested with pytest, and it’s a large project, thousands of tests. Steps for speedup Parallelizing test execution with pytest-xdist 67% time reduction --numprocesses=auto allows for using all cores DB isolation - cool example of how to config postgress to give each test worker it’s on db They used pytest-sugar to help with visualization, as xdist defaults to quite terse output Use Python 3.12’s sys.monitoring to speed up coverage instrumentation 53% time reduction Nice example of using COVERAGE_CORE=sysmon Optimize test discovery Always use testpaths Sped up collection time. 66% reduction (collection was 10% of time) Not a huge savings, but it’s 1 line of config Eliminate unnecessary imports Use python -X importtime Examine dependencies not used in testing. Their example: ddtrace A tool they use in production, but it also has a couple pytest plugins included Those plugins caused ddtrace to get imported Using -p:no ddtrace turns off the plugin bits Notes from Brian: I often get questions about if pytest is useful for large projects. Short answer: Yes! Longer answer: But you’ll probably want to speed it up I need to extend this article with a general purpose “speeding up pytest” post or series. -p:no can also be used to turn off any plugin, even builtin ones. Examples include nice to have developer focused pytest plugins that may not be necessary in CI CI reporting plugins that aren’t needed by devs running tests locally Michael #2: People aren’t talking enough about how most of OpenAI’s tech stack runs on Python Original article: Building, launching, and scaling ChatGPT Images Tech stack: The technology choices behind the product are surprisingly simple; dare I say, pragmatic! Python: most of the product’s code is written in this language. FastAPI: the Python framework used for building APIs quickly, using standard Python type hints. As the name suggests, FastAPI’s strength is that it takes less effort to create functional, production-ready APIs to be consumed by other services. C: for parts of the code that need to be highly optimized, the team uses the lower-level C programming language Temporal: used for asynchronous workflows and operations inside OpenAI. Temporal is a neat workflow solution that makes multi-step workflows reliable even when individual steps crash, without much effort by developers. It’s particularly useful for longer-running workflows like image generation at scale Michael #3: PyCon Talks on YouTube Some talks that jumped out to me: Keynote by Cory Doctorow 503 days working full-time on FOSS: lessons learned Going From Notebooks to Scalable Systems And my Talk Python conversation around it. (edited episode pending) Unlearning SQL The Most Bizarre Software Bugs in History The PyArrow revolution in Pandas And my Talk Python episode about it. What they don't tell you about building a JIT compiler for CPython And my Talk Python conversation around it (edited episode pending) Design Pressure: The Invisible Hand That Shapes Your Code Marimo: A Notebook that "Compiles" Python for Reproducibility and Reusability And my Talk Python episode about it. GPU Programming in Pure Python And my Talk Python conversation around it (edited episode pending) Scaling the Mountain: A Framework for Tackling Large-Scale Tech Debt Brian #4: Optimizing Python Import Performance Mostly pay attention to #'s 1-3 This is related to speeding up a test suite, speeding up necessary imports. Finding what’s slow Use python -X importtime <the reset of the command Ex: python -X importtime ptyest Techniques Lazy imports move slow-to-import imports into functions/methods Avoiding circular imports hopefully you’re doing that already Optimize __init__.py files Avoid unnecessary imports, heavy computations, complex logic Notes from Brian Some questions remain open for me Does module aliasing really help much? This applies to testing in a big way Test collection imports your test suite, so anything imported at the top level of a file gets imported at test collection time, even if you only are running a subset of tests using filtering like -x or -m or other filter methods. Run -X importtime on test collection. Move slow imports into fixtures, so they get imported when needed, but NOT at collection. See also: option -X in the standard docs Consider using import_profile Extras Brian: PEPs & Co. PEP is a ‘backronym”, an acronym where the words it stands for are filled in after the acronym is chosen. Barry Warsaw made this one up. There are a lot of “enhancement proposal” and “improvement proposal” acronyms now from other communities pythontest.com has a new theme More colorful. Neat search feature Now it’s excruciatingly obvious that I haven’t blogged regularly in a while I gotta get on that Code highlighting might need tweaked for dark mode Michael: git-bug Pyrefly follow up Joke: There is hope.
#433 Dev in the Arena
Topics covered in this episode: git-flight-rules Uravelling t-strings neohtop Introducing Pyrefly: A new type checker and IDE experience for Python 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: git-flight-rules What are "flight rules"? A guide for astronauts (now, programmers using Git) about what to do when things go wrong. Flight Rules are the hard-earned body of knowledge recorded in manuals that list, step-by-step, what to do if X occurs, and why. Essentially, they are extremely detailed, scenario-specific standard operating procedures. [...] NASA has been capturing our missteps, disasters and solutions since the early 1960s, when Mercury-era ground teams first started gathering "lessons learned" into a compendium that now lists thousands of problematic situations, from engine failure to busted hatch handles to computer glitches, and their solutions. Steps for common operations and actions I want to start a local repository What did I just commit? I want to discard specific unstaged changes Restore a deleted file Brian #2: Uravelling t-strings Brett Cannon Article walks through Evaluating the Python expression Applying specified conversions Applying format specs Using an Interpolation class to hold details of replacement fields Using Template class to hold parsed data Plus, you don’t have to have Python 3.14.0b1 to try this out. The end result is very close to an example used in PEP 750, which you do need 3.14.0b1 to try out. See also: I’ve written a pytest version, Unravelling t-strings with pytest, if you want to run all the examples with one file. Michael #3: neohtop Blazing-fast system monitoring for your desktop Features Real-time process monitoring CPU and Memory usage tracking Beautiful, modern UI with dark/light themes Advanced process search and filtering Pin important processes Process management (kill processes) Sort by any column Auto-refresh system stats Brian #4: Introducing Pyrefly: A new type checker and IDE experience for Python From Facebook / Meta Another Python type checker written in Rust Built with IDE integration in mind from the beginning Principles Performance IDE first Inference (inferring types in untyped code) Open source I mistakenly tried this on the project I support with the most horrible abuses of the dynamic nature of Python, pytest-check. It didn’t go well. But perhaps the project is ready for some refactoring. I’d like to try it soon on a more well behaved project. Extras Brian: Python: The Documentary Official Trailer Tim Hopper added Setting up testing with ptyest and uv to his “Python Developer Tooling Handbook” For a more thorough intro on pytest, check out courses.pythontest.com pocket is closing, I’m switching to Raindrop I got one question about code formatting. It’s not highlighted, but otherwise not bad. Michael: New course! Polars for Power Users: Transform Your Data Analysis Game Apache Airflow 3.0 Released Paste 5 Joke: Theodore Roosevelt’s Man in the Arena, but for programming