old_contents: from nltk.sentiment.vader import SentimentIntensityAnalyzer
  vader_analyzer = SentimentIntensityAnalyzer()
  
  print vader_analyzer.polarity_scores('I am happy')
  
new_contents: from nltk.sentiment.vader import SentimentIntensityAnalyzer
  
  
  class SentimentAnalyzer:
      def __init__(self):
          self.analyzer = SentimentIntensityAnalyzer()
  
      def get_polarity(self, string):
          return self.analyzer.polarity_scores(string)
  
  if __name__ == '__main__':
      analyzer = SentimentAnalyzer()
      string = "I'm happy!!!"
      print "polarity:", analyzer.get_polarity(string)
  
subject: Make vader.py a module