它返回str而不是list的原因是csv编写器将始终执行与str(['a','b'])等效的操作，即"['a', 'b']",c,d，因此您可以使用ast.literal_eval从字符串列表中获取列表，如下所示，对于第一个元素-

import csv
import ast
i = [['a', 'b'], 'c', 'd']
with open('a.csv', 'a', newline='', encoding='utf-8') as file:
    writer = csv.writer(file, delimiter=';')
    writer.writerow(i)

file.close()
with open('a.csv', 'r', newline='', encoding='utf-8') as file:
    for i in csv.reader(file, delimiter=';'):
        i[0] = ast.literal_eval(i[0])
        print(type(i),type(i[0]), i[0][0])

你可以使用for循环，就像这样：
示例a.csv

hello, aloha, hola
bye, aloha, adios

Python代码：

import csv

col1 = []
with open('a.csv')  as file:
    r = csv.reader(file)
    for row in r:
        col1.append(row[0])

print(col1)  # => ['hello', 'bye']

或者，您也可以使用列表解析：

import csv

col1 = []
with open('a.csv')  as file:
    r = csv.reader(file)
    col1 = [row[0] for row in r]

print(col1)  # => ['hello', 'bye']