Python/Heads or Tails

from random import choice

patterns = {}
lasthuman = 'tails'
num = 5
a = ['heads','tails']
patterns['heads'] = ['heads']
patterns['tails'] = ['tails']

print 'Think of a number between 1 and 10'
while num < 11:

    robo = choice(patterns[lasthuman])
    print "I guess",robo
    print "----------------------------------"
    human = str(raw_input('What did it land on > '))
    a.append(human)
    patterns[lasthuman].append(human)
    lasthuman = human

""" Machine statistically guesses whether next toss will be heads or tails by choosing randomly from two list of previous results; if previous was head append result to head list etc """