Python：csv

csv读取

方式一：内置 csv 模块

例

no,path,score
0,"['""灵吉菩萨""', '""孙悟空""', '""小鼍龙""', '""龙王""']",1.0
1,"['""徒弟""', '""孙悟空""', '""小鼍龙""', '""龙王""']",1.0
2,"['""乌鸡国王""', '""孙悟空""', '""小鼍龙""', '""龙王""']",1.0

import csv
import ast

filename = 'data.csv'

with open(filename, mode='r', encoding='utf-8') as f:
    reader = csv.DictReader(f)
    for row in reader:
        # 将字符串转换为列表
        path_list = ast.literal_eval(row['path'])
        
        print(f"编号: {row['no']}")
        print(f"路径: {path_list}")
        print(f"分数: {row['score']}")
        print("-" * 20)

方式二：pandas

风格1

import pandas as pd
import ast

# 1. 读取 CSV 文件
# 如果你的文件名是 'data.csv'
df = pd.read_csv('data.csv')

# 2. 将 'path' 列从字符串转换为真正的 Python 列表对象
# 因为 read_csv 会把 ['A', 'B'] 读成一个长字符串
df['path'] = df['path'].apply(ast.literal_eval)

# 3. 打印结果
print("--- 数据类型 ---")
print(df.dtypes)
print("\n--- 数据内容 ---")
print(df)

# 访问某一行具体的路径
print("\n第一行的路径列表:", df.loc[0, 'path'])
print("路径中的第一个元素:", df.loc[0, 'path'][0])

风格2

import pandas as pd
import ast

# 在读取的同时，直接告诉 pandas：'path' 这一列要用 ast.literal_eval 处理
df = pd.read_csv('data.csv', converters={'path': ast.literal_eval})

# 现在 df['path'] 已经是真正的列表了
print(df['path'].iloc[0][1]) # 直接访问列表中间的元素

csv存储

方式一：内置 csv 模块

列表

import csv

rows = [
    ["id", "name", "score"],
    [1, "Alice", 95],
    [2, "Bob", 88],
    [3, "Charlie", 92],
]

with open("output.csv", "w", newline="", encoding="utf-8") as f:
    writer = csv.writer(f)
    writer.writerows(rows)

print("CSV 写入完成")

说明：

• newline=""：必须，否则 Windows 下会多空行
• encoding="utf-8"：防止中文乱码

字典

import csv

data = [
    {"id": 1, "name": "Alice", "score": 95},
    {"id": 2, "name": "Bob", "score": 88},
    {"id": 3, "name": "Charlie", "score": 92},
]

fieldnames = ["id", "name", "score"]

with open("output.csv", "w", newline="", encoding="utf-8") as f:
    writer = csv.DictWriter(f, fieldnames=fieldnames)
    writer.writeheader()
    writer.writerows(data)

print("CSV 写入完成")

方式二：pandas

如果后面还要做分析、排序、统计，这个更舒服。

import pandas as pd

data = [
    {"id": 1, "name": "Alice", "score": 95},
    {"id": 2, "name": "Bob", "score": 88},
    {"id": 3, "name": "Charlie", "score": 92},
]

df = pd.DataFrame(data)
df.to_csv("output.csv", index=False, encoding="utf-8")

print("CSV 写入完成")

常见坑

问题	正确做法
多空行	open(..., newline="")
中文乱码	encoding="utf-8" 或 Excel 用 utf-8-sig
Excel 打开乱码	encoding="utf-8-sig"
覆盖写	用 "w"
追加写	用 "a"