python csv copy列 [英] python csv copy column

问题描述

我有一个包含以下文件的文件

  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 
  

我想复制列email并创建新列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，我尝试了几个脚本，但如果有一个更好的方法，那么请让我知道。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
对于reader1中的行：
 [2：3] ==uid：
 writer1.append（Email2）
 else：
 writer1.writerow（row + [row [2：3]]）
 

这里是最后的脚本，只有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，open（outFile，'wb'）为fp_out1：
writer = csv .writer（fp_out1，delimiter =，）
reader = csv.reader（fp_in1，delimiter =，）
读取器中的col：
del col [6：]
writer.writerow（col）
header = next（阅读器）
writer.writerow（headers + ['email2']）
读取器中的行：
如果len row）> 3：
email = email.split（'@'，1）[0] +'@ hotmail.com'
writer.writerow（row + [email]）

解决方案

如果在阅读器上调用 next（） ;使用它来复制头。复制电子邮件栏很简单：

  import csv 
 
 infilename = r'c：\ Python27 \scripts\colnewfile.csv'
 outfilename = r'c：\Python27\scripts\final.csv'
 
打开（infilename，'rb'）as fp_in，open（outfilename，'wb'）as fp_out：
 reader = csv.reader（fp_in，delimiter =，）
 headers = next（reader）＃读取第一行
 
 writer = csv.writer（fp_out，delimiter =，）
 writer.writerow（headers + ['email2']）
 
读取行：
如果len（row）> 3：
＃确保有至少4列
 email = row [3] .split（'@'，1）[0] +'@ hotmail.com'
 writer。这个代码将电子邮件地址分成第一个<$ c $（$）
 
 $ p $ c> @  sign，接受拆分的第一部分，并在其后添加 @ hotmail.com ：
 >>> '[e-mail]'.split（'@'，1）[0] 
'example'
>>>> '[e-mail]'.split（'@'，1）[0] +'@ hotmail.com'
'[e-mail]'
  pre> 
 
 
以上产生：
  first_name，last_name，uid，电子邮件，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 
  
。
 
I have a file containing following 
first_name,last_name,uid,email,dep_code,dep_name
john,smith,jsmith,[e-mail],finance,21230
john,king,jking,[e-mail],human resource,31230
I want to copy column "email" and create a new column "email2" and then replace gmail.com from column email2 to hotmail.com

I'm new to python so need help from experts, I tried few script, but if there is a better way to do it then please let me know. The original file contains 60000 rows. 
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]])
Here is the final script, only problem is that it does not complete the entire outfile, it only show 61409 rows, whereas in the input file there are 61438 rows.                                      

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

with open(inFile, 'rb') as fp_in1, open(outFile, 'wb') as fp_out1:
    writer = csv.writer(fp_out1, delimiter=",")
    reader = csv.reader(fp_in1, delimiter=",")
    for col in reader:
        del col[6:]
        writer.writerow(col)
    headers = next(reader)
    writer.writerow(headers + ['email2'])
    for row in reader:
        if len(row) > 3:
            email = email.split('@', 1)[0] + '@hotmail.com'
        writer.writerow(row + [email])
解决方案
If you call next() on the reader you get one row at at a time; use that to copy over the headers. Copying the email column is easy enough:
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])
This code splits the email address on the first @ sign, takes the first part of the split and adds @hotmail.com after it:
>>> '[e-mail]'.split('@', 1)[0]
'example'
>>> '[e-mail]'.split('@', 1)[0] + '@hotmail.com'
'[e-mail]'
The above produces:
first_name,last_name,uid,email,dep_code,dep_name,email2
john,smith,jsmith,[e-mail],finance,21230,[e-mail]
john,king,jking,[e-mail],human resource,31230,[e-mail]
for your sample input.

                        
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