Simple Markov

markov.py

import sys
import random

if __name__ == "__main__":
    state, num_steps = sys.argv[1], int(sys.argv[2])
    count = dict()
    count['a'], count['b'] = 0, 0

    for i in range(num_steps):
        count[state] += 1
        flip = random.random()
        if state == 'a' and flip <= 2.0/3:
            state = 'b'
        elif state == 'b' and flip <= 1.0/4:
            state = 'a'

    for x in count:
        print x, count[x]/(1.0*num_steps)