Compiling Python to WebAssembly with py2wasm

Slides of the presentation for the Wasm I/O conference in March 15, 2024.

1. Compiling Python to WebAssembly Syrus Akbary March 2024 And how we got here…
2. Who am I?
7. I want to make it universal! Circa 2018
9. Can I compile Graphene to WebAssembly? WebAssembly could help on the quest of having an universal GraphQL library!
10. such cool WOW very Wasm
11. ❤ Python Backend: + > Running at:
12. Could we run Wasmer’s Python backend performantly?
13. Use the CPython interpreter in Wasm
14. But… performance sucked Using the CPython interpreter was not the fastest solution
15. How to improve performance
16. Making Python go brr brr in Wasm • Use a Python subset that can be compiled into performant code • Use JIT inside of Python • Use Static Analysis to optimize code
17. Python subset • Codon ➡ github.com/exaloop/codon • RPython ➡ rpython.readthedocs.io • Cython Optimize a smaller set ✅ Can be compiled to very performant code ❌ Doesn’t support the full syntax or modules JS Equivalent: Assemblyscript
18. RPython Transforms the typed code into C, and then compiles it $ rpython hello_world.py hello-world-c.c
19. But… dictionaries couldn’t be dynamic Using unmodi f ied code was challenging
20. Codon Transforms a subset of Python code into LLVM IR
21. But… many incompatibilities with Python Using unmodi f ied code was challenging
22. Python JITs • Pypy ➡ pypy.org Compile the hot paths ✅ Really fast speeds ❌ Needs to warm up ❌ Not trivial to support with Wasm (but possible) JS Equivalent: V8, JasvascriptCore, SpiderMonkey
23. PyPy JIT *Don’t miss Dmitry’s talk on JITs on Wasm with Spidermonkey 🔗 pypyjs.org
24. But… it would take a bit more time to get right! JITs are possible, but not trivial -> More development time!
25. Static Analysis • Mypy & Mypy-c ➡ mypy-lang.org • Nuitka ➡ github.com/Nuitka/Nuitka Performant code based on the types ✅ Mostly compatible with Python ❌ Only 1.5-3x faster ❌ Complex to get right ❌ Larger binaries JS Equivalent: Static Hermes, TypescriptCompiler
26. MyPy-C 🔗 mypyc.readthedocs.io
27. Nuitka Python to CPython transpiler • It supports most Python programs. Transpiles Python code into the corresponding CPython calls • It can even work as a code obfuscator (no one will be able to decompile your program!)
28. But… but… no buts, let’s try it! Everything promising, so far…
29. Demo time! Using Nuitka natively
30. Will it compile to WASI? If Nuitka generates C code, and then uses a compiler… can we just switch the compiler?
31. Not that simple! ❌ Not compatible with Python 3.12+ ❌ Doesn’t support cross compiling to di ff erent architectures (64 to 32 bits)
32. 🥁 (prepare for big announcement)
33. Announcing py2wasm 🎉 A Python to WebAssembly compiler (using Nuitka)
34. 1. Install py2wasm 2. Run
35. It’s fast… Very fast 3x faster
36. Plan Ahead • Compile Wasmer Django backend to Wasm via py2wasm • Use WASIX for full asyncio, threads and sockets support • py2wasm working fully inside of wasmer Future plans!
37. Stay tuned in wasmer.io :) Upcoming post coming (very) soon!
38. Thank you 🙏 @syrusakbary / @wasmerio