dumb markov thing

blue.py

from random import random

class node:
    name = '' # the token's value
    followingStates = None # <next name>: <num of times seen>
    numSeen = 0 # number of times token has been seen

    def __init__(self, name):
        self.name = name
        self.numSeen = 1
        self.followingStates = {}

    def incState(self, state):
        if state in self.followingStates:
            self.followingStates[state] += 1
        else:
            self.followingStates[state] = 1

    def getNextState(self):
        idx = self.numSeen * random()
        for nextName, nextSeen in self.followingStates.iteritems():
            if idx <= nextSeen:
                return nextName
            idx -= nextSeen

    def __str__(self):
        return self.name

class markov:
    lookup = {} # <node name>: <node instance>
    currentNode = None

    def incWord(self, word):
        if word not in self.lookup:
            self.lookup[word] = node(word)

        if self.currentNode is not None:
            self.currentNode.incState(word)

        self.currentNode = self.lookup[word]

    def produceChain(self, n):
        outputNode = self.getStartNode()

        res = []

        for x in range(n):

            res += [str(outputNode)]

            # try to get another state, return if you hit a terminal?
            try:
                outputNode = self.lookup[outputNode.getNextState()]
            except:
                return res

        return res

    def populateTable(self, stream):

        for word in stream:
            self.incWord(word)

        self.currentNode = None

    def getStartNode(self):
        idx = int(random()*len(self.lookup))
        return self.lookup.values()[idx]

m = markov()
m.populateTable(['i', 'am', 'not', 'a', 'crook'])
print m.produceChain(5)