A somewhat untidy Python script to generate a 1d cellular automata based on an MD5 hash.

cellular_automata.py

"""
Example output: http://www.flickr.com/photos/sneeu/5448646680/
"""


import hashlib


RULES = {
    4: {
        (0, 0, 0, ): 0,
        (0, 0, 1, ): 1,
        (0, 1, 0, ): 1,
        (0, 1, 1, ): 1,
        (1, 0, 0, ): 0,
        (1, 0, 1, ): 0,
        (1, 1, 0, ): 1,
        (1, 1, 1, ): 1,
    },
    107: {
        (0, 0, 0, ): 1,
        (0, 0, 1, ): 0,
        (0, 1, 0, ): 0,
        (0, 1, 1, ): 1,
        (1, 0, 0, ): 0,
        (1, 0, 1, ): 1,
        (1, 1, 0, ): 0,
        (1, 1, 1, ): 0,
    }
}

def rule(initial, rule=4, odd=0):
    ret = []

    for i, c in enumerate(initial):
        l = r = odd

        if i > 0:
            l = initial[i - 1]
        if (i + 1) < len(initial):
            r = initial[i + 1]

        n = RULES[rule][(l, c, r)]
        ret.append(n)

    return ret


def rows(initial, iterations):
    r = [initial]
    for i in xrange(0, iterations):
        initial = r[-1]
        r.append(rule(initial, 107, i % 2))
    return r


def main():
    initial = []
    n = int(hashlib.md5('[email protected]').hexdigest(), 16)
    power = 1

    while power <= n:
        initial.insert(0, n & power and 1 or 0)
        power = power * 2

    initial = [0] * 50 + initial + [0] * 50

    for r in rows(initial, 30):
        print ''.join([c and '#' or ' ' for c in r])


if __name__ == '__main__':
    main()