Calculate the level of similarity between two strings, on a scale from 0 to 1

similarity.py

"""
Credit to sissi_lauty for this algorithm
Original: http://stackoverflow.com/a/15077476
"""

from math import sqrt

def similarity(x, y):
    # find length of shorter of the two strings
    n=min(len(x), len(y))
    
    common=0
    
    # for 0 to n characters, check if characters x[i] and y[i] are the same
    for i in range(n):
        if (x[i]==y[i]):
            # add 1 to number of characters from 0 to n in common
            common+=1
    
    # calcluate similarity between x and y using number of corresponding characters        
    return common/sqrt(len(x)*len(y))