def sorenson_dice_sim(u, v):
    """
    Computes the Sørensen-Dice similarity coefficient between sets u and v.
    sim = (2 * intersection(u, v)) / (|u| + |v|)
    Where |s| is the number of items in set s
    params:
        u, v: sets to compare
    returns:
        float between 0 and 1, where 1 represents perfect
            similarity and 0 represents no similarity
    """
    ix = len(u.intersection(v))
    zero = 1e-10
    sim = (2 * ix) / (len(u) + len(v) + zero)
    return sim