将文本(单个字母)附加到文本文件中每行的末尾

时间:2014-09-18 22:06:38

标签: python csv text

以下是我正在使用的文本文件的示例:

437868313,2436413,Wyatt,Trenton,08/21/2003,211000010262002,211000010262002,2014,01,54435A000,510,Social Studies (Grade 5),08/14/2013,5-2,02,0,02,02,01,,,,,,100,05/29/2014,
437868313,2436413,Wyatt,Trenton,08/21/2003,211000010262002,211000010262002,2014,01,53235A000,500,Science (Grade 5),08/14/2013,5-2,02,0,02,02,01,,,,,,100,05/29/2014,
437868313,2436413,Wyatt,Trenton,08/21/2003,211000010262002,211000010262002,2014,01,58035A000,560,Physical Education (Grade 5),08/14/2013,5-2,02,0,02,02,01,,,,,,1,05/29/2014,

我想简单地添加字母' S'到每一行的结尾。所以,上面有3条记录。在2014年5月29日之后,我想插入S.所以每条记录都会像:

437868313,2436413,Wyatt,Trenton,08/21/2003,211000010262002,211000010262002,2014,01,54435A000,510,Social Studies (Grade 5),08/14/2013,5-2,02,0,02,02,01,,,,,,100,05/29/2014,S

我意识到这将是如此简单的转换为CSV并使用excel,但我在传输回到txt时遇到各种格式问题。想用python来解决它。我试图使用追加,据我所知,写将覆盖我现有的文件:

myFile = open("myFile.txt", "a")
    for line in myFile:
        myFile.write('S')

我经常不使用python,我想知道如何将其编入索引,因此它从第2行开始,并在逗号之后追加该行的最后一行,就像我上面提到的那样。

5 个答案:

答案 0 :(得分:8)

您需要逐行读取文件,然后再次逐行输出。这比使用CSV甚至是真正让我害怕的电子表格处理软件更简单。

with open('input.txt', 'r') as istr:
    with open('output.txt', 'w') as ostr:
        for i, line in enumerate(istr):
            # Get rid of the trailing newline (if any).
            line = line.rstrip('\n')
            if i % 2 == 0:
                line += 'S'
            print(line, file=ostr)

如果您仍在使用Python 2,请使用

ostr.write(line + '\n')

而不是print

更新:如果您要追加每个(而不是其他所有)行,只需使用:

with open('input.txt', 'r') as istr:
    with open('output.txt', 'w') as ostr:
        for line in istr:
            line = line.rstrip('\n') + 'S'
            print(line, file=ostr)

答案 1 :(得分:3)

打开文件进行读取和写入,并枚举输入文件。 Idenfity使用mod 2的偶数行。将s追加到偶数行并写入输出文件。

with open('myfile.txt', 'rb') as infile, with open('outfile.txt', 'wb') as outfile:
    for lineno, line in enumerate(infile):
        if lineno % 2 == 0:
            line = line + 'S'
        outfile.write(line)

OP根据他的编辑想要每条记录,因此无需测试偶数行。

import os

with open('myfile.txt', 'rb') as infile, with open('outfile.txt', 'wb') as outfile:
    for line in infile:
       line = line.replace(os.linesep, 'S' + os.linesep)
       outfile.write(line)

答案 2 :(得分:0)

最简单的方法是将文件作为一个块打开,并用逗号和换行符替换逗号和换行符。

open("data.txt").read().replace(',\n','S,\n').write()

答案 3 :(得分:0)

试试这个:

filename = "file.txt"
file = open(filename, "r")
for line in file:
    print line.replace("\n","S\n")

答案 4 :(得分:0)

试试这个:

myFile = open("myFile.txt", "a")
Colist = str(myFile.read()).split('\n')
for line in Colist:
    myFile.write(line + 'S' + '\n')