如何在文本文件中查找数据，如果不存在，则查找最接近的值

def find_closest_value(target, filename):
    closest_value = None
    min_difference = float('inf')  # 初始差值设为无穷大

    with open(filename, 'r') as file:
        for line in file:
            value = float(line.strip())  # 假设文件每行包含一个数值，将其转换为浮点数

            difference = abs(target - value)  # 计算目标值与当前值的差值

            if difference < min_difference:  # 如果当前差值小于之前最小差值
                min_difference = difference
                closest_value = value

    return closest_value

# 示例用法
target_value = 3.7
filename = 'data.txt'
closest_value = find_closest_value(target_value, filename)
print(f"最接近的值为：{closest_value}")