import random
import re
WORD_RE = re.compile(r'''(?:(?:an?|the) )?[\w']+[.,:;!?—-]*''', re.U | re.M)
class DissociatedPressman:
    def __init__(self, filename):
        with open(filename, 'r') as f:
            source = WORD_RE.findall(f.read())
        chains = {}
        starts = set()
        for index, word in enumerate(source):
            next_index = (index + 1) % len(source)
            chains.setdefault(word, []).append(source[next_index])
            if word[0] == word[0].upper():
                starts.add(word)
        self.chains = chains
        self.starts = list(starts)
    def generate(self, words=100, style=True):
        word = random.choice(self.starts)
        chain = self.chains[word]
        result = [word]
        while len(result) < words or (style and not word.endswith(('.', '!', '?'))):
            word = random.choice(chain)
            result.append(word)
            chain = self.chains[word]
        return ' '.join(result)
if __name__ == '__main__':
    pressman = DissociatedPressman('ulysses.txt')
    print(pressman.generate())