将csv文件加载到lis

Question

我有一个python脚本，它首先将list写入CSV文件，然后立即将CSV文件加载到另一个list。

我只尝试了将list写入CSV的代码，它可以工作，CSV文件的内容是制表符分隔的，其内容如下：

car house wife

但如果把所有这些放在一起：

import csv

// write list to CSV file, it works!
the_list=["car","house","wife"]
the_file = open("my_file.csv", 'w+')
writer = csv.writer(the_file, delimiter='\t')
writer.writerow(the_list)


// read CSV file & load into list
my_file = open("my_file.csv", 'r')
reader = csv.reader(my_file, delimiter='\t')
my_list = list(reader)
print(my_list)

我打印了一张空名单：[]，怎么了？

Answer 1

您没有关闭要写入的文件，因此读取操作找不到要读取的数据。您可以使用with语句来确保文件已关闭。

import csv

# write list to CSV file, it works!
the_list=["car","house","wife"]
with open("my_file.csv", 'w') as outfile:
    writer = csv.writer(outfile, delimiter='\t')
    writer.writerow(the_list)


# read CSV file & load into list
with open("my_file.csv", 'r') as my_file:
    reader = csv.reader(my_file, delimiter='\t')
    my_list = list(reader)
    print(my_list)

如果你这样做，阅读工作很好。

➜  python test.py
[['car', 'house', 'wife']]