二分查找python版

# python版二分法：

import random, math

def bsearch(v, data, pre=0):
    l = len(data)
    if l <= 0:
        return -1;
    half = int(math.floor(l/2))
    c = v - data[half]
    if c > 0:
        return bsearch(v, data[half + 1:], pre + half + 1)
    elif c < 0:
        return bsearch(v, data[:half], pre)
    else:
        return pre + half



def main():
    DATA = range(0, 100, 2)
    target = DATA[random.randint(0, len(DATA))]

    print bsearch(target, DATA)
    print bsearch(0, [0,1,2])