不使用pandas如何从CSV文件中将行数据分组为目标列表

Python自带标准库即可完成需求，无需安装任何第三方依赖，以下是两种可直接运行的实现方案：

方案1：使用内置csv模块（更规范，适配复杂CSV场景） #

import csv

# 初始化字典存储品牌和对应车型的映射
brand_model_map = {}

with open("cars.csv", "r", encoding="utf-8") as f:
    reader = csv.reader(f)
    for row in reader:
        # 跳过空行、注释行
        if not row or row[0].strip().startswith("#"):
            continue
        brand = row[0].strip()
        model = row[1].strip()
        # 新增品牌或追加对应车型
        if brand not in brand_model_map:
            brand_model_map[brand] = []
        brand_model_map[brand].append(model)

# 转换为要求的输出格式
brands = list(brand_model_map.keys())
models = list(brand_model_map.values())

方案2：直接读取文件解析（无需导入csv模块，适配简单格式CSV） #

brand_model_map = {}

with open("cars.csv", "r", encoding="utf-8") as f:
    for line in f:
        line = line.strip()
        # 跳过空行、注释行
        if not line or line.startswith("#"):
            continue
        brand, model = line.split(",")
        brand = brand.strip()
        model = model.strip()
        if brand not in brand_model_map:
            brand_model_map[brand] = []
        brand_model_map[brand].append(model)

brands = list(brand_model_map.keys())
models = list(brand_model_map.values())

输出验证 #

运行后打印两个变量即可得到目标格式：

print(brands)
print(models)

输出结果：

["Bugatti","VW","Opel"]
[["Veyron","Chiron"], ["Golf","Passat","Polo","Caddy"], ["Insignia"]]

注：Python3.7及以上版本字典默认保留插入顺序，输出顺序和CSV内品牌首次出现的顺序完全一致

内容的提问来源于stack exchange，提问作者perry