def get_jaccard_sim(str1, str2):
    """
    Jaccard similarity:
    Also called intersection over union is defined as size of intersection
    divided by size of union of two sets.
    """
    a = set(str1.split())
    b = set(str2.split())
    c = a.intersection(b)
    return float(len(c)) / (len(a) + len(b) - len(c))