compund score in vader

def polarity_scores(self, text):
    """
    Return a float for sentiment strength based on the input text.
    Positive values are positive valence, negative value are negative
    valence.
    """
    sentitext = SentiText(text)
    #text, words_and_emoticons, is_cap_diff = self.preprocess(text)

    sentiments = []
    words_and_emoticons = sentitext.words_and_emoticons
    for item in words_and_emoticons:
        valence = 0
        i = words_and_emoticons.index(item)
        if (i < len(words_and_emoticons) - 1 and item.lower() == "kind" and \
            words_and_emoticons[i+1].lower() == "of") or \
            item.lower() in BOOSTER_DICT:
            sentiments.append(valence)
            continue

        sentiments = self.sentiment_valence(valence, sentitext, item, i, sentiments)

    sentiments = self._but_check(words_and_emoticons, sentiments)