Test performance of string slice, buffer() and memoryview() for access a substring.

timeit_substring.py

"Performance test comparing string slice to buffer() and memoryview()."
import os
import timeit

TESTDATA = os.urandom(16 * 1000)

def test_control(s=TESTDATA):
    "Use a slice to access a substring of s"
    t = s[2:-1]
    return len(t)

def test_buffer(s=TESTDATA):
    "Use buffer() built in to access a substring of s"
    l = len(s) - 3
    b = buffer(s, 2, l)
    return len(b)

def test_view(s=TESTDATA):
    "Use a memoryview() to access a substring of s"
    m = memoryview(s)
    v = m[2:-1]
    return len(v)

if __name__=='__main__':
    loops = 100000

    t1 = timeit.Timer('test_control()', 'from __main__ import test_control')
    print "(control) %.2f usec/pass" % (1e6 * t1.timeit(number=loops)/loops)

    t2 = timeit.Timer('test_buffer()', 'from __main__ import test_buffer')
    print "(buffer)  %.2f usec/pass" % (1e6 * t2.timeit(number=loops)/loops)

    t3 = timeit.Timer('test_view()', 'from __main__ import test_view')
    print "(view)    %.2f usec/pass" % (1e6 * t3.timeit(number=loops)/loops)