Cython Introduction

benchmark.py

from timeit import default_timer as timer

class benchmark(object):

    def __init__(self, msg, fmt="%0.3g"):
        self.msg = msg
        self.fmt = fmt

    def __enter__(self):
        self.start = timer()
        return self

    def __exit__(self, *args):
        t = timer() - self.start
        print(("%s : " + self.fmt + " seconds") % (self.msg, t))
        self.time = t

commands.sh

python setup.py build_ext --inplace
python test.py

main.pyx

def prime_finder_vanilla(amount):
    primes = []

    found = 0
    number = 2
    while found < amount:
        for x in primes:
            if number % x == 0:
                break

        else:
            primes.append(number)
            found += 1

        number += 1

    return primes

def prime_finder_optimized(int amount):

    cdef int number, x, found
    cdef int primes[100000]

    amount = min(amount, 100000)

    found = 0
    number = 2
    while found < amount:
        for x in primes[:found]:
            if number % x == 0:
                break

        else:
            primes[found] = number
            found += 1

        number += 1

    return_list = [p for p in primes[:found]]
    return return_list

setup.py

from setuptools import setup
from Cython.Build import cythonize

setup(
        ext_modules=cythonize('main.pyx')
        )

test.py

import main
from benchmark import benchmark

with benchmark("vanilla"):
   main.prime_finder_vanilla(10000) 


with benchmark("optimized"):
   main.prime_finder_optimized(10000)