attempt at random.shuffle using mergesort with random comparison

gistfile1.txt

# Copyright (c) 2012 the authors listed at the following URL, and/or
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# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
# 
# Retrieved from: http://en.literateprograms.org/Merge_sort_(Python)?oldid=18716

import random
import os
random.seed(os.urandom(1))
def merge(left, right):
    result = []
    i ,j = 0, 0
    while i < len(left) and j < len(right):
        #if left[i] <= right[j]:
        if random.random() < 0.5 :
            result.append(left[i])
            i += 1
        else:
            result.append(right[j])
            j += 1

    result += left[i:]
    result += right[j:]
    return result



def mergesort(lst):
    if len(lst) <= 1:
        return lst
    middle = int( len(lst) / 2 )
    left = mergesort(lst[:middle])
    right = mergesort(lst[middle:])
    return merge(left, right)


counts = [0,0,0,0,0,0,0,0,0,0,0,0,0]
if __name__ == "__main__":
    z = 0
    while(z < 100000):
        z = z + 1
        x = [0, 4, 8, 3, 6, 7, 4, 2, 1, 9, 4, 5]
        y = mergesort(x)
        counts[y.index(0)] = counts[y.index(0)] + 1 

    for i in range(0,9):
        print counts[i] 

sample output

wespiser@home:projects>python mg.py 
12694
10731
9706
8976
8452
7833
7611
7423
7063

wespiser@home:projects>python mg.py 
12572
10770
9938
9036
8299
7896
7605
7332
6936

wespiser@home:projects>python mg.py 
12554
11009
9795
8909
8513
7893
7614
7269
7048