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AFINN-based sentiment analysis for Node.js


AFINN-based sentiment analysis for Node.js

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Sentiment is a Node.js module that uses the AFINN-165 wordlist to perform sentiment analysis on arbitrary blocks of input text. Sentiment provides several things:

  • Performance (see benchmarks below)
  • The ability to append and overwrite word / value pairs from the AFINN wordlist
  • A build process that makes updating sentiment to future versions of the AFINN word list trivial


npm install sentiment


var sentiment = require('sentiment');
var r1 = sentiment('Cats are stupid.');
console.dir(r1);        // Score: -2, Comparative: -0.666 
var r2 = sentiment('Cats are totally amazing!');
console.dir(r2);        // Score: 4, Comparative: 1 

Adding / overwriting words

You can append and/or overwrite values from AFINN by simply injecting key/value pairs into a sentiment method call:

var sentiment = require('sentiment');
var result = sentiment('Cats are totally amazing!', {
    'cats': 5,
    'amazing': 2  
console.dir(result);    // Score: 7, Comparative: 1.75 


The primary motivation for designing sentiment was performance. As such, it includes a benchmark script within the test directory that compares it against the Sentimental module which provides a nearly equivalent interface and approach. Based on these benchmarks, running on a MacBook Pro with Node 0.12.7, sentiment is twice as fast as alternative implementations:

sentiment (Latest) x 544,714 ops/sec ±0.83% (99 runs sampled)
Sentimental (1.0.1) x 269,417 ops/sec ±1.06% (96 runs sampled)

To run the benchmarks yourself, simply:

make benchmark


npm test