Du Toit Spies

I'm an MSc student at UCT in Cape Town, South Africa. My research focuses on creating a backend for Cython that uses the new HPy API to bind C code to Python, rather than the existing C API.

Accepted Talks:

Implementing an HPy Backend for Cython

HPy (https://hpyproject.org/) is a new API for extending Python with C, and is intended as an alternative to the existing C API. It is designed to have zero overhead on CPython while being much faster on alternate implementations such as GraalPy (https://www.graalvm.org/python/) and PyPy (https://pypy.org/) (don’t worry, all of this will be explained in the talk).

Many Python tools still use the C API, which harms their performance on GraalPy and PyPy. One such tool is Cython. Cython is a program that compiles Python code to C code for improved performance. The generated C files use the C API. We created an HPy backend for Cython, which replaces instances of the C API with the equivalent HPy code. This involved changing C API functions and structures to the equivalent ones in HPy, as well as reorganising the Cython source code to let it generate HPy-compliant code. We can create modules using HPy to handle data structures, function calls, and class creation with Cython.

After benchmarking our code on the C API and HPy on both CPython and GraalPy, we found that our HPy version of Cython can perform on GraalPy at speeds equivalent to the C API on CPython for some benchmarks, while on the other benchmarks our backend performed better than the C API on GraalPy, while still underperforming CPython. We also identified parts of HPy that need to be optimised further to ensure performance gains on all benchmarks.


Thinkst Canary
Python Software Foundation SARAO
AWS City of Cape Town
Afrolabs Centre for High Performance Computing
Black Python Devs