title: Python -extract positive words from a string using sentiment vader
body: <p>Is it possible to iterate through a string of words, classify them as positive, negative, or neutral using sentiment vader, then if they are positive append these positive words to a list?  The for loop below is the non working code for what I am trying to accomplish.  I am a beginner at Python so would greatly appreciate it if anyone could provide guidance on how to make this work.  </p>
  
  <pre><code>import nltk
  from nltk.sentiment.vader import SentimentIntensityAnalyzer
  test_subset=['20170412', 'great', 'bad', 'terrible', 'dog', 'stop', 'good']
  test_subset_string_fixed=" ".join(str(x) for x in test_subset)
  sid = SentimentIntensityAnalyzer()
  pos_word_list=[]
  
  for word in test_subset_string_fixed:
      if (sid.polarity_scores(test_subset_string_fixed)).key() == 'pos':
          pos_word_list.append(word)
  </code></pre>
  
  <p>Thank you very much for the help.</p>