My binary search entry, 40 minutes, all tests pass so far.

#!/usr/bin/env python

"""
See http://reprog.wordpress.com/2010/04/19/are-you-one-of-the-10-percent/
"""

import math

def bsearch(search_value, input_array):
    """
    Assume array is sorted, min at [0] and max at [-1]
    """

    # Ending conditions
    if len(input_array) <= 0:
        return False
    if search_value < input_array[0]:
        return False
    if search_value > input_array[-1]:
        return False

    split_index = int(math.floor(len(input_array) / 2))

    if input_array[split_index] == search_value:
        return True

    if search_value > input_array[split_index]:
        return bsearch(search_value, input_array[split_index+1:])
    else:
        return bsearch(search_value, input_array[0:split_index])

Test code:
#!/usr/bin/env python

import unittest
import logging

from pfh_bsearch import bsearch

class BsearchTester(unittest.TestCase):
    def setUp(self):
        logging.basicConfig(level=logging.INFO, format='%(asctime)s %(levelname)s [%(funcName)s] %(message)s')

    def test_404(self):
        a = [1,2,3]
        b = 4
        rc = bsearch(b, a)
        self.failUnlessEqual(rc, False)

        b = 0
        rc = bsearch(b, a)
        self.failUnlessEqual(rc, False)

        a = [1,2,3,4]
        rc = bsearch(b, a)
        self.failUnlessEqual(rc, False)

    def test_find(self):
        a = [0,1,3,5]
        b = 1
        rc = bsearch(b, a)
        self.failUnlessEqual(rc, True)
        b = 0
        rc = bsearch(b, a)
        self.failUnlessEqual(rc, True)
        b = 3
        rc = bsearch(b, a)
        self.failUnlessEqual(rc, True)
        b = 5
        rc = bsearch(b, a)
        self.failUnlessEqual(rc, True)

    def test_corner_cases(self):
        a = []
        b = 42
        rc = bsearch(b, a)
        self.failUnlessEqual(rc, False)

        a = [1]
        rc = bsearch(b, a)
        self.failUnlessEqual(rc, False)

suite = unittest.TestLoader().loadTestsFromTestCase(BsearchTester)
unittest.TextTestRunner(verbosity=2).run(suite)