Cosine similarity of two string vectors

cosine-match.py

import math
import re
import sys
from collections import Counter

WORD = re.compile(r"\w+")


def get_cosine(vec1, vec2):
    intersection = set(vec1.keys()) & set(vec2.keys())
    numerator = sum([vec1[x] * vec2[x] for x in intersection])

    sum1 = sum([vec1[x] ** 2 for x in list(vec1.keys())])
    sum2 = sum([vec2[x] ** 2 for x in list(vec2.keys())])
    denominator = math.sqrt(sum1) * math.sqrt(sum2)

    if not denominator:
        return 0.0
    else:
        return float(numerator) / denominator


def text_to_vector(text):
    words = WORD.findall(text)
    return Counter(words)


def main():

    infile_path = sys.argv[1]
    query_file_path = sys.argv[2]

    with open(query_file_path, "r") as query_file:

        with open(infile_path, "r") as infile:
            q_l_no = 1
            for query in query_file:
                q_l_no += 1

                l_no = 1
                lines = []
                for line in infile:
                    l_no += 1
                    vector1 = text_to_vector(query)
                    vector2 = text_to_vector(line)

                    cosine = get_cosine(vector1, vector2)

                    lines.append((cosine, line, l_no))

                s_lines = sorted(lines, key=lambda x: x[0], reverse=True)
                print(str(q_l_no) + ": " + query)
                print(
                    "\n".join([str(l_no) + ": " + str(l[0]) + ", " + l[1] for l in s_lines]))
                print("\n")


if __name__ == '__main__':
    main()