Tuesday, March 27, 2018

Leysin Winter Sprint 2018: review

Like every year, the PyPy developers and a couple of newcomers gathered in Leysin, Switzerland, to share their thoughts and contribute to the development of PyPy.

As always, we had interesting discussions about how we could improve PyPy, to make it the first choice for even more developers. We also made some progress with current issues, like compatibility with Python 3.6 and improving the performance of CPython extension modules, where we fixed a lot of bugs and gained new insights about where and how we could tweak PyPy.

We were very happy about the number of new people who joined us for the first time, and hope they enjoyed it as much as everyone else.


We worked on the following topics (and more!):
  • Introductions for newcomers
  • Python 3.5 and 3.6 improvements
  • CPyExt performance improvements and GC implementation
  • JIT: guard-compatible implementation
  • Pygame performance improvements
  • Unicode/UTF8 implementation
  • CFFI tutorial/overview rewrite
  • py3 test runners refactoring
  • RevDB improvements
The weather was really fine for most of the week, with only occasional snow and fog. We started our days with a short (and sometimes not so short) planning session and enjoyed our dinners in the great restaurants in the area. Some of us even started earlier and continued till late night. It was a relaxed, but also very productive atmosphere. On our break day on Wednesday, we enjoyed the great conditions and went skiing and hiking.


  • Arianna
  • Jean-Daniel
  • Stefan Beyer
  • Floris Bruynooghe
  • Antonio Cuni
  • RenĂ© Dudfield
  • Manuel Jacob
  • Ronan Lamy
  • Remi Meier
  • Matti Picus
  • Armin Rigo
  • Alexander Schremmer
Leysin is easily reachable by Geneva Airport, so feel free to join us next time!