Precomputing a series of 5 As and 5 Bs in a secret random order.

rands.py

# Usage:
# python rands.py
#
# head -n 1 output
# head -n 2 output
# etc...

import random
f = open('output', 'w')
lst = [0]*5 + [1]*5
for i in range(10):
  idx = random.randint(0, len(lst)-1)
  f.write(str(lst[idx]) + '\n')
  del lst[idx]
f.close()