alt Hacker NewsI was a bit nervous about this trend when it started picking up because I care about Pyodide (Python running via WebAssembly) and libraries that use PyO3 might not work in Pyodide.
Thankfully that's now been mostly solved - you can compile and publish WASM builds of Rust or C extensions on PyPI now and a Pyodide can then use them.
Here's the WASM build of the Rust-including Pydantic-core package for example: https://pypi.org/project/pydantic_core/#pydantic_core-2.49.0...
I'm kind of surprised to hear that was a concern because my perception is that PyO3 is more analogous to wrapping native C code in Python libraries (which is pretty well established since long before either Rust or WASM), and Pyodide seems more like something for use in browsers rather on the server-side. When I looked into this earlier this year, trying to run Python via WASM on the server side with Pyodide had a bunch of hoops I needed to jump through, and it ended up being a lot simpler to use a build of Python from one of the core Python contributors that directly targeted WASM.