old_contents: import sys
  import re
  
  def main(argv):
      # Message to perform sentiment analysis on
      message = argv[0] if len(argv) > 0 else ""
  
      if message == "":
          print("Usage: python analyze.py [message]")
          sys.exit(1)
  
      # Load the positive and negative words
      words = {}
      with open("words/positive.txt") as file:
          for line in file:
              words[line.rstrip()] = 1
  
      with open("words/negative.txt") as file:
          for line in file:
              words[line.rstrip()] = -1
  
      # Perform the sentiment analysis
      score = 0
      found = 0
      for w in message.split():
          # Only keep alphanumeric characters and some punctuation.
          w = re.sub(r'[^\-\'+\w]', '', w).lower()
          if w in words:
              score += words[w]
              found += 1
  
      print(round(score / float(found) if found != 0 else 0, 2))
  
  if __name__ == "__main__":
      main(sys.argv[1:])
  
new_contents: import sys
  import re
  
  def main(argv):
      # Load the positive and negative words
      words = {}
      with open("words/positive.txt") as file:
          for line in file:
              words[line.rstrip()] = 1
  
      with open("words/negative.txt") as file:
          for line in file:
              words[line.rstrip()] = -1
  
      # Perform the sentiment analysis
      for message in sys.stdin:
          score = 0
          found = 0
          for w in message.split():
              # Only keep alphanumeric characters and some punctuation.
              w = re.sub(r'[^\-\'+\w]', '', w).lower()
              if w in words:
                  score += words[w]
                  found += 1
  
          print(round(score / float(found) if found != 0 else 0, 2))
  
  if __name__ == "__main__":
      main(sys.argv[1:])
  
subject: Read from standard input and perform on each line