fixed tuple unpacking error when adding new entries to lexicon.txt

[f0lie]

When adding new entries to vader_lexicon.txt, Unix text editors will add a newline to the end of files to comply with standards. The problem is that when nltk reads the entire file then vader splits the lines, the code reads an empty entry. When python attempts to unpack the line into a tuple, it crashes.

The resulting error looks something like the text I attached below.

I fixed the issue by striping a newline within the body of SentimentIntensityAnalzyer.make_lex_dict(). Nltk gives a single line of text when it reads the file, so rstrip just removes the very last newline.

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-7-d54d1cf92423> in <module>()
      2 # NOTE VADER FAILS WITH LONGER MESSAGES ESPECIALLY MULTIPLE SENTENCES
      3 from nltk.sentiment.vader import SentimentIntensityAnalyzer
----> 4 vader = SentimentIntensityAnalyzer('./vader_lexicon.txt')
      5 scored = feedback['FEEDBACK_TX'].apply(vader.polarity_scores)
      6 

~/feedback-sentiment/.env/lib/python3.6/site-packages/nltk/sentiment/vader.py in __init__(self, lexicon_file)
    203     def __init__(self, lexicon_file="sentiment/vader_lexicon.zip/vader_lexicon/vader_lexicon.txt"):
    204         self.lexicon_file = nltk.data.load(lexicon_file)
--> 205         self.lexicon = self.make_lex_dict()
    206 
    207     def make_lex_dict(self):

~/feedback-sentiment/.env/lib/python3.6/site-packages/nltk/sentiment/vader.py in make_lex_dict(self)
    211         lex_dict = {}
    212         for line in self.lexicon_file.split('\n'):
--> 213             (word, measure) = line.strip('\n').split('\t')[0:2]
    214             lex_dict[word] = float(measure)
    215         return lex_dict

ValueError: not enough values to unpack (expected 2, got 1)

[f0lie]

This is the only line that actually changed. The rest is my editor removing extra whitespaces. Sorry about that.

[dariencupit]

I think I have ran into this exact same error when attempting to use pyinstaller on our program that uses vaderSentiment. I am puzzled as to why this pull request is still up, even though it is 2 years old.

[cjhutto]

Thanks so much for finding this, and making a change for the better. I've incorporated the fix :)