eloraburns

# Assuming Python >=2.5, <3.0
import os
from random import randint
num_random_bits = 9
with open('f', 'r+') as f:
    f.seek(0, os.SEEK_END)
    length = f.tell()-1
    for _ in range(num_random_bits):
        place = randint(0, length)
        f.seek(place, os.SEEK_SET)