Python 怎么在csv文件中加入一列数据？

这是一个把最后一列重复一次的例子：

import csv

with open('test.csv') as csvfile:    rows = csv.reader(csvfile)    with open('test1.csv','w', newline='') as f:        writer = csv.writer(f)        for row in rows:           row.append(row[len(row)-1])           writer.writerow(row)

Python是纯粹的自由软件， 源代码和解释器CPython遵循 GPL(GNU General Public License)协议[2]  。Python语法简洁清晰，特色之一是强制用空白符(white space)作为语句缩进。

# -*- coding: utf8 -*-

import csv

l = [['1', 'Wonderful Spam'],['2', 'Lovely Spam']]

#模拟数据写入一个csv

with open('eggs.csv', 'w', newline='') as csvfile:

spamwriter = csv.writer(csvfile, delimiter=',',quotechar='"', quoting=csv.QUOTE_MINIMAL)for row in l:

spamwriter.writerow(row)

#从文件读取

l=[]

with open('eggs.csv', newline='') as csvfile:

spamreader = csv.reader(csvfile, delimiter=',', quotechar='"')for row in spamreader:

l = l + [row]

#把两列拼接增加为第三列写回到文件

with open('eggs.csv', 'w', newline='') as csvfile:

spamwriter = csv.writer(csvfile, delimiter=',',quotechar='"', quoting=csv.QUOTE_MINIMAL)for row in l:

print(row)

spamwriter.writerow(row + [row[0]+row[1]])

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