我怎样才能摆脱这个错误，我用一个代码来查找最近的邻居？

def find_nearest_neighbor(data, target):
    min_distance = float('inf')
    nearest_neighbor = None

    for point in data:
        distance = calculate_distance(point, target)
        if distance < min_distance:
            min_distance = distance
            nearest_neighbor = point

    return nearest_neighbor

def calculate_distance(point1, point2):
    # 计算两个点之间的距离
    # 可以使用欧氏距离、曼哈顿距离等算法
    # 这里以欧氏距离为例
    distance = ((point1[0] - point2[0]) ** 2 + (point1[1] - point2[1]) ** 2) ** 0.5
    return distance

# 示例数据
data = [(1, 2), (3, 4), (5, 6), (7, 8)]
target = (4, 5)

nearest_neighbor = find_nearest_neighbor(data, target)
print("最近的邻居是：", nearest_neighbor)