What are some algorithms for comparing how similar two strings are?

Question

I need to compare strings to decide whether they represent the same thing. This relates to case titles entered by humans where abbreviations and other small details may di

Answer 1

Another algorithm that you can consider is the Simon White Similarity:

def get_bigrams(string):
    """
    Take a string and return a list of bigrams.
    """
    if string is None:
        return ""

    s = string.lower()
    return [s[i : i + 2] for i in list(range(len(s) - 1))]

def simon_similarity(str1, str2):
    """
    Perform bigram comparison between two strings
    and return a percentage match in decimal form.
    """
    pairs1 = get_bigrams(str1)
    pairs2 = get_bigrams(str2)
    union = len(pairs1) + len(pairs2)

    if union == 0 or union is None:
        return 0

    hit_count = 0
    for x in pairs1:
        for y in pairs2:
            if x == y:
                hit_count += 1
                break
    return (2.0 * hit_count) / union