def test_sorensen():
"""Sorensen coefficients are correct."""
data_a = [4, 0, 1, 3]
data_b = [3, 1, 0, 5]
sim_score = similarity.sorensen(data_a, data_b)
assert round(sim_score, 3) == 0.885
def test_sorensen_empty():
"""Sorensen coefficient of two empty lists is 0."""
assert similarity.sorensen([], []) == 0
