Question

I would like to know how to compare 2 different strings through a function in Python. More specifically, how similar 2 different strings are, and their similarity as a percentage (the letters that appear in both strings). Thanks in advance.

Answer 1

def pctSame(s1,s2):
    # Make sorted arrays of string chars
    s1c = [x for x in s1]
    s1c.sort()
    s2c = [x for x in s2]
    s2c.sort()
    i1 = 0
    i2 = 0
    same = 0
    # "merge" strings, counting matches
    while ( i1<len(s1c) and i2<len(s2c) ):
        if s1c[i1]==s2c[i2]:
            same += 2
            i1 += 1
            i2 += 1
        elif s1c[i1] < s2c[i2]:
            i1 += 1
        else:
            i2 += 1
    # Return ratio of # of matching chars to total chars
    return same/float(len(s1c)+len(s2c))