somecython

qsortest.pyx

cimport cython
from libc.stdlib cimport calloc, free


cdef extern from "qsortest.h":
    void qsort_char(unsigned char *base, size_t nmemb)


def mvqsort(unsigned char[:] vofi):
    qsort_char(&vofi[0], vofi.shape[0])


def cqsort(charlist):
    cdef int charnum = len(charlist)
    cdef unsigned char *chararray = <unsigned char *>calloc(charnum, sizeof(unsigned char))

    if chararray is NULL:
        raise MemoryError

    cdef i
    for i in range(charnum):
        chararray[i] = charlist[i]

    qsort_char(chararray, charnum)

    for i in range(charnum):
        charlist[i] = chararray[i]

runs.txt

(cython)mrw@hammal:~/src/python/qsortest$ PYTHONPATH=build/lib.linux-x86_64-2.7/ python -m timeit -n 100 -s 'import test' 'test.test_cqsort()'
100 loops, best of 3: 48.2 msec per loop
(cython)mrw@hammal:~/src/python/qsortest$ PYTHONPATH=build/lib.linux-x86_64-2.7/ python -m timeit -n 100 -s 'import test' 'test.test_mvqsort()'
100 loops, best of 3: 22.8 msec per loop

setup.py

from distutils.core import setup
from Cython.Build import cythonize

setup(
    ext_modules=cythonize("qsortest.pyx")
)

test.py

import random
import qsortest

unsorted_chars = bytearray(chr(i) for i in xrange(254)) * 1000
random.shuffle(unsorted_chars)
sorted_chars = bytearray(chr(i)
                         for i in
                         xrange(254)
                         for _ in xrange(1000))


def test_cqsort():
    qsortest.cqsort(unsorted_chars)
    assert sorted_chars == unsorted_chars


def test_mvqsort():
    qsortest.mvqsort(unsorted_chars)
    assert sorted_chars == unsorted_chars