The Cython language makes writing C extensions for the Python language
as easy as Python itself. Cython is a source code translator based on
the well-known Pyrex, but supports more cutting edge functionality and
optimizations.

The Cython language is very close to the Python language (and most
Python code is also valid Cython code), but Cython additionally supports
calling C functions and declaring C types on variables and class
attributes. This allows the compiler to generate very efficient C code
from Cython code.

This makes Cython the ideal language for writing glue code for external
C libraries, and for fast C modules that speed up the execution of
Python code.

See also: https://github.com/cython/cython