On Mon, Aug 6, 2018 at 11:49 AM Ronald Oussoren via Python-Dev firstname.lastname@example.org wrote:
I have no strong opinion on using Cython for tests or in the stdlib, other than that it is a fairly large dependency. I do think that adding a “Cython-lite” tool the CPython distribution would be less ideal, creating and maintaining that tool would be a lot of work without clear benefits over just using Cython.
Speaking of which, Dropbox is working on a new compiler they call "mypyc".
mypyc will compile type-annotated Python code to an optimized C. The first goal is to compile mypy with it to make it faster, so I hope that the project will be completed. Essentially, mypyc will be similar to Cython, but mypyc is a *subset of Python*, not a superset. Interfacing with C libraries can be easily achieved with cffi. Being a strict subset of Python means that mypyc code will execute just fine in PyPy. They can even apply some optimizations to it eventually, as it has a strict and static type system.
I'd be more willing to start using mypyc+cffi in CPython stdlib *eventually*, than Cython now. Cython is a relatively complex and still poorly documented language. I'm speaking from experience after writing thousands of lines of Cython in uvloop & asyncpg. In skillful hands Cython is amazing, but I'd be cautious to advertise and use it in CPython.
I'm also -1 on using Cython to test C API. While writing C tests is annoying (I wrote a fair share myself), their very purpose is to make third-party tools/extensions more stable. Using a third-party tool to test C API to track regressions that break third-party tools feels wrong.