dissoc.py

#!/usr/bin/python
"Second-order Markov-chain text generator."
import sys, random

def words(infile):
    for line in infile:
        for word in line.split(): yield intern(word)
freqs = {}
state = [None, None]
for word in words(sys.stdin):
    freqs.setdefault(tuple(state), []).append(word)
    state.append(word)
    state.pop(0)

for _ in xrange(1000):
    if tuple(state) not in freqs: state = [None, None]
    word = random.choice(freqs[tuple(state)])
    print word,
    state.append(word)
    state.pop(0)