Question

我有一个包含以下内容的文件

first_name,last_name,uid,email,dep_code,dep_name
john,smith,jsmith,jsmith@gmail.com,finance,21230
john,king,jking,jjing@gmail.com,human resource,31230

我想复制“email”列并创建一个新列“email2”，然后将gmail.com从列email2替换为hotmail.com

我是python的新手，所以需要专家的帮助，我尝试了很少的脚本，但是如果有更好的方法，请告诉我。原始文件包含60000行。

with open('c:\\Python27\\scripts\\colnewfile.csv', 'rb') as fp_in1, open('c:\\Python27\\scripts\\final.csv', 'wb') as fp_out1:
    writer1 = csv.writer(fp_out1, delimiter=",")
    reader1 = csv.reader(fp_in1, delimiter=",")
    domain = "@hotmail.com"
    for row in reader1:
        if row[2:3] == "uid":
            writer1.append("Email2")
        else:
            writer1.writerow(row+[row[2:3]])

这是最终的脚本，唯一的问题是它没有完成整个outfile，它只显示61409行，而在输入文件中有61438行。

inFile ='c：\ Python27 \ scripts \ in-093013.csv' outFile ='c：\ Python27 \ scripts \ final.csv'

打开（inFile，'rb'）为fp_in1，打开（outFile，'wb'）为fp_out1： writer = csv.writer（fp_out1，delimiter =“，”） reader = csv.reader（fp_in1，delimiter =“，”）对于读者来说： del col [6：] writer.writerow（COL） headers = next（读者） writer.writerow（headers + ['email2']）读者行：如果len（行）＆gt; 3： email = email.split（'@'，1）[0] +'@ hotmail.com' writer.writerow（row + [email]）

Answer 1

如果您在阅读器上拨打next()，您可以同时获得一行;用它来复制标题。复制电子邮件列非常简单：

import csv

infilename = r'c:\Python27\scripts\colnewfile.csv'
outfilename = r'c:\Python27\scripts\final.csv'

with open(infilename, 'rb') as fp_in, open(outfilename, 'wb') as fp_out:
    reader = csv.reader(fp_in, delimiter=",")
    headers = next(reader)  # read first row

    writer = csv.writer(fp_out, delimiter=",")
    writer.writerow(headers + ['email2'])

    for row in reader:
        if len(row) > 3:
            # make sure there are at least 4 columns
            email = row[3].split('@', 1)[0] + '@hotmail.com'
        writer.writerow(row + [email])

此代码在第一个@符号上拆分电子邮件地址，获取拆分的第一部分并在其后添加@hotmail.com：

>>> 'example@gmail.com'.split('@', 1)[0]
'example'
>>> 'example@gmail.com'.split('@', 1)[0] + '@hotmail.com'
'example@hotmail.com'

以上产生：

first_name,last_name,uid,email,dep_code,dep_name,email2
john,smith,jsmith,jsmith@gmail.com,finance,21230,jsmith@hotmail.com
john,king,jking,jjing@gmail.com,human resource,31230,jjing@hotmail.com

您的样本输入。

Answer 2

这可以使用pandas非常干净地完成。在这里：

In [1]: import pandas as pd

In [3]: df = pd.read_csv('your_csv_file.csv')

In [4]: def rename_email(row):
   ...:     return row.email.replace('gmail.com', 'hotmail.com')
   ...:

In [5]: df['email2'] = df.apply(rename_email, axis=1)

In [6]: """axis = 1 or ‘columns’: apply function to each row"""

In [7]: df
Out[7]:
  first_name last_name     uid             email        dep_code  dep_name              email2
0       john     smith  jsmith  jsmith@gmail.com         finance     21230  jsmith@hotmail.com
1       john      king   jking   jjing@gmail.com  human resource     31230   jjing@hotmail.com

In [8]: df.to_csv('new_update_email_file.csv')

python csv复制列

2 个答案: