def test_partition_around_index():
    'partition_around_index should split a list into two lists around an index'
    assert (partition_around_index([1, 2, 3, 4], 2) == ([1, 2], [4]))
    assert (partition_around_index([1, 2, 3, 4], 0) == ([], [2, 3, 4]))
    assert (partition_around_index([1, 2, 3, 4], 3) == ([1, 2, 3], []))
    with pytest.raises(ValueError):
        partition_around_index([1, 2, 3, 4], 4)
partition_around_index should split a list into two lists around an index
def test_partition_around_index():
    
    assert (partition_around_index([1, 2, 3, 4], 2) == ([1, 2], [4]))
    assert (partition_around_index([1, 2, 3, 4], 0) == ([], [2, 3, 4]))
    assert (partition_around_index([1, 2, 3, 4], 3) == ([1, 2, 3], []))
    with pytest.raises(ValueError):
        partition_around_index([1, 2, 3, 4], 4)