new_contents: """Read lines from a file, feed them into the markov generator, and then
  generate a few lines.
  
  Usage:
    python from_file.py <input_filename> <num_lines_to_generate>
  """
  import sys
  
  import sujmarkov
  
  
  def extract_sentences(input_file):
      # Each line is a sentence.
      #
      for raw_line in input_file:
          line = raw_line.lower().strip()
  
          # For now, ignore punctuation.
          #
          line = line.replace(",", "").replace("-", "").replace('"', '')
  
          for sub_line in line.split("."):
              raw_sentence = sub_line.split(" ")
  
              sentence = [word for word in raw_sentence if word and word.strip() != ""]
              if sentence:
                  yield sentence
  
  
  if __name__ == "__main__":
      m = sujmarkov.Markov(n=2)
  
      with open(sys.argv[1], "r") as input_file:
          for sentence in extract_sentences(input_file):
              m.add(sentence)
  
      num_required = int(sys.argv[2])
      num_done = 0
  
      while num_done < num_required:
          generated_sentence = " ".join(m.generate())
          print generated_sentence
          num_done += 1
  
subject: Add a util to generate sentences from a file