[andreasvc]

But why do you prefer it over Cython, since it can also wrap "actual, pure C, and dynamically [call] it from Python"?

What is the vectorization problem? Both Cython and Julia allow you to write tight loops and have them perform well.

[Derbasti]

In CFFI, you write either Python, or C. In Cython, you additionally write a weird dialect that is neither C nor Python. I prefer straight C over Cython.