dummy_sentiment.py

# Simple sentiment analysis with lots and lots of problems. For answer to Quora thread:
# https://www.quora.com/Would-it-be-possible-for-an-undergraduate-like-me-to-create-a-sentiment-analysis-program
import sys
from collections import counter


with open(sys.argv[1]) as file_:
    positive_text = file_.read()
with open(sys.argv[2]) as file_:
    negative_text = file_.read()
with open(sys.argv[3]) as file_:
    problem_text = file_.read()

positive_freqs = Counter(positive_text.split())
negative_freqs = Counter(negative_text.split())
problem_freqs = Counter(problem_text.split())

positive_score = 0.0
negative_score = 0.0
for word, freq in problem_freqs.items():
    pos_freq = positive_freqs.get(word, 0.01)
    neg_freq = negative_freqs.get(word, 0.01)
    positive_score += freq * (pos_freq / (pos_freq + neg_freq))
    negative_score += freq * (neg_freq / (pos_freq + neg_freq))

if positive_score >= negative_score:
    print("It's positive!", positive_score, negative_score)
else:
    print("It's negative!", positive_score, negative_score)