Cython example To compile into a shared library, execute: python setup.py build_ext --inplace

helloworld.pyx

cdef extern from "math.h":
	double sin(double)

cdef double f(double x) except *:
	return sin(x**2)

def integrate(double a, double b, int N):
	cdef int i
	cdef double s, dx
	s = 0
	dx = (b-a)/N
	for i in range(N):
		s += f(a + i*dx)
	return s*dx

setup.py

from distutils.core import setup
from distutils.extension import Extension
from Cython.Distutils import build_ext

ext_modules = [Extension("helloworld", ["helloworld.pyx"])]

setup(
name = 'Cython Example',
cmdclass = {'build_ext': build_ext},
ext_modules = ext_modules
)

test.py

import helloworld

print helloworld.integrate(0,1,1000)