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Pyodide: a Python distribution based on WebAssembly

Pyodide powers xlwings Lite, a free Excel add-in that you can install from Excel’s add-in store with a single click. It outperforms Microsoft’s official Python in Excel solution in every coceivable way: price, privacy, speed, can install packages, can access the internet, can access local files, doesn’t have a usage quota, can automate Excel and create native UDFs. See https://lite.xlwings.org

an hour agofzumstein

Pyodide is one of the hidden gems of the Python ecosystem. It's SO good at what it does, and it's nearly 8 years old now so it's pretty mature.

I love using Pyodide to build web UIs for trying out new Python libraries. Here's one I built a few weeks ago to exercise my pure-Python SQLite AST parser, for example: https://tools.simonwillison.net/sqlite-ast

It's also pretty easy[1] to get C or Rust libraries that have Python bindings compiled to a WebAssembly wheel that Pyodide can then load.

Here's a bit of a nutty example - the new Monty Python-like sandbox library (written in Rust) compiled to WASM and then loaded in Pyodide in the browser: https://simonw.github.io/research/monty-wasm-pyodide/pyodide...

[1] OK, Claude Code knows how to do it.

3 hours agosimonw

How do you call those C/Rust libraries compiled from to webassembly from Python/Pyodide?

3 hours agoiamcreasy

You have to turn them into WebAssembly wheels, then you can import them as if they were regular Python modules.

3 hours agosimonw

It works surprisingly well in terms of writing python for native execution, and then trying to share on the web and having it Just Work TM. Unfortunately, when I want python it's because I want numpy, scipy and friends, and once you bring them on board pyodide load times are long. As an example comparison: a face turning octahedron puzzle in python + pyodide, loads in 10 seconds https://cubes.hgreer.com/fto.html . Meanwhile, a megaminx puzzle in javascript (statically generated by python) loads in 200 ms https://cubes.hgreer.com/ssg/output.html

3 hours agoQuadmasterXLII

There's also xeus-cpp which is cpp based on wasm. Xeus-cpp and pyodide are the backends for Jupyterlite [1] kernels in browser.

It's actually a very good way to teach coding in python/c++(11, 17 or even 23), explore language features or your own library within browser and allow students to execute code by hosting just some static html pages and some assets without any backend.

1. https://jupyter.org/try-jupyter/lab/

3 hours agodevsda

I tried to make a version of this using Zig once, but ran out of steam: https://cowasm.org/

44 minutes agowilliamstein

Everyone runs out of steam when it comes to WebAssembly. I used to wonder in the past why we hear so little about it, until I realised that nobody is really using it. Granted, there are those who use WebAssembly, but if we compare it to HTML, CSS, JavaScript, then WebAssembly is simply not existing anywhere near that level. After soon-to-be 10 years, that is very disappointing.

31 minutes agoshevy-java

That is very cool. Has anyone made a nice beginner's learning environment out of it? Seems like it would solve some of the extra friction that makes it hard to get started.

2 hours agoyjftsjthsd-h

I played around with it to build a little "intro to python" walkthrough on my blog a while back. It worked surprisingly well! I had a little trouble giving users the ability to ctrl-c if they accidentally wrote an infinite loop though lol (piodide supports it I just didn't implement it): https://cfu288.com/blog/2024-05_cwc-intro-to-python/

an hour agocfu28

Jupyterlite - a lot of jupyter trial versions use it.

an hour agowisty

Yea, I even built online ide based on Pyodide. Insane peace of software. You can try here: playcode.io/python

3 hours agoianberdin

I've used it to put together a browser app to program walkie-talkies: https://codeplug.org

2 hours agojasiek

WebAssembly will reach a breakthrough in the same year as GNU Hurd will dominate, together with the Desktop-Linux-of-the-year.

32 minutes agoshevy-java

Anyone using it with nodejs to make a sandbox for code agents?

5 hours agojacob019

ChatGPT's Canvas uses Pyodide for sandboxing, but it's not designed for coding agents. Node.js environment is usually better for agents. Pyodide restricts server-side functionality, and fetching external URLs often needs proxying due to sandbox. By the way, pyodide is still good option for interactive visualizer or deploying small webapps require data processing.

4 hours agob89kim

For that purpose I think most people are using bubblewrap or seatbelt/sandbox-exec with CPython.

4 hours agojcheng

From https://news.ycombinator.com/item?id=47171887 re: [agent] sandboxing :

pydantic/monty, vercel-labs/just-bash, amla sandbox, csl-core, microsandbox, workerd, wasmtime-mte

containers/bubblewrap: https://github.com/containers/bubblewrap#sandboxing

The bubblewrap readme mentions containers as binaries with binctr; I guess without overlayfs or other file-level re-deduplication due to the container fs in the binary.

Perhaps similarly, also TIL UKI are easier for UEFI Secure Boot to check signatures on than (kernel, initrd) pairs

5 minutes agowesturner

no but it works great in conjunction with observable and d3js for pretty interactives!

4 hours agoyawnxyz

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