过滤包含数据的最后一行之后的行，保留间隙

def filter_last_line(file_path):
    with open(file_path, 'r') as file:
        lines = file.readlines()

    # 找到最后一行包含数据的索引
    last_data_line_index = len(lines) - 1
    while last_data_line_index >= 0:
        if lines[last_data_line_index].strip() != '':
            break
        last_data_line_index -= 1

    # 删除最后一行及其之后的行
    filtered_lines = lines[:last_data_line_index + 1]

    # 将过滤后的行写入新文件或覆盖原文件
    with open(file_path, 'w') as file:
        file.writelines(filtered_lines)