markov.py

    
PUNC = ['!', '?', '.']
    
import random

class Markov(object):
       
       def __init__(self, open_file):
               self.cache = {}
               self.open_file = open_file
               self.words = self.file_to_words()
               self.word_size = len(self.words)
               self.seed()
               self.database()

       def seed(self, seed=None):
           self._seed = seed or "gotta catch em' all!"
       
       def file_to_words(self):
               self.open_file.seek(0)
               data = self.open_file.read()
               words = data.split()
               return words
               
       
       def triples(self):
               """ Generates triples from the given data string. So if our string were
                               "What a lovely day", we'd generate (What, a, lovely) and then
                               (a, lovely, day).
               """
               
               if len(self.words) < 4:
                       return
               
               for i in range(len(self.words) - 3):
                       yield (self.words[i], self.words[i+1], self.words[i+2], self.words[i+3])
                       
       def database(self):
               for w1, w2, w3, w4 in self.triples():
                       key = (w1, w2, w3)
                       if key in self.cache:
                               self.cache[key].append(w4)
                       else:
                               self.cache[key] = [w4]
                               
       def generate_markov_text(self, size=25):
               # print "generating"
               random.seed(self._seed)
               seed = random.randint(0, self.word_size-4)
               seed_word, next_word, third_word = self.words[seed], self.words[seed+1], self.words[seed+2]
               w1, w2, w3 = seed_word, next_word, third_word
               gen_words = []
               for i in range(size):
                       gen_words.append(w1)
                       w1, w2, w3 = w2, w3, random.choice(self.cache[(w1, w2, w3)])
               gen_words.append(w3)

               first = 0
               last = 0
               for i, word in enumerate(gen_words):
                 if first == 0 and '.' in word:
                   first = i+1

                 if '.' in word:
                   last = i+1

               gen_words = gen_words[first:last]

               return ' '.join(gen_words)
    
def get_text(seed=None):
    markov = Markov(open("markov/descriptions.txt"))
    markov.seed(seed)
    text = markov.generate_markov_text(size=50)
    # print text
    
    return text


#print get_text()