Question

我想删除文件中的某些特定行。以下代码似乎不起作用。没有抛出任何错误，但此代码不会删除要删除的行。

#!/usr/bin/python
import argparse
import re
import string

p = argparse.ArgumentParser()
p.add_argument("input", help="input the data in format ip:port:name", nargs='*')  
args = p.parse_args()
kkk_list = args.input # ['1.1.1.1:443:myname', '2.2.2.2:443:yourname']


def getStringInFormat(ip, port, name):
    formattedText = "HOST Address:{ip}:PORT:{port}\n"\
                    "   server tcp\n"\
                    "   server {ip}:{port} name {name}\n\n".format(ip=ip, 
                                                                port=port, 
                                                              name=name)

    return formattedText

with open("file.txt", "r+") as f:
    fileContent = f.read()

    # below two lines delete old content of file
    f.seek(0)
    f.truncate()

    for kkk in kkk_list:
        ip, port, name = re.split(":|,", kkk)

        stringNeedsToBeDeleted = getStringInFormat(ip, port, name)
        fileContent = fileContent.replace(stringNeedsToBeDeleted, "")

    f.write(fileContent)

我尝试删除的文件内容如下所示。请注意第2行和第3行之前的空格

------------do not delete this line------

HOST Address:1.1.1.1:PORT:443\n"\

     server tcp\n"\
     server 1.1.1.1:443 name myname1

--------------- do not delete this line either

如果脚本成功，文件应该如下所示，其间只有一个新行。

------------do not delete this line------

------------do not delete this line either ----

任何见解？

Answer 1

你正在文件编辑循环中正确地做所有事情，这意味着如果你实际上没有替换任何东西，因为你正在寻找的字符串不存在。的确，当你告诉我们你正在寻找这个字符串时：

------------do not delete this line------

HOST Address:1.1.1.1:PORT:443\n"\

     server tcp\n"\
     server 1.1.1.1:443 name myname1

--------------- do not delete this line either

它似乎与您尝试将其匹配的字符串匹配：

formattedText = "HOST Address:{ip}:PORT:{port}\n"\
                "   server tcp\n"\
                "   server {ip}:{port} name {name}\n\n"

请记住，为了用当前代码替换此字符串，字符串必须完全匹配，在这种情况下，我不会在＆＃34; HOST之间看到\ n Addess ...＆＃34;和＆＃34; server tcp \ n＆＃34; \或\ lines。但我怀疑那些只是你的格式错误。

如果你真的想找到这个问题的根源，我建议你找一个你确定要删除的字符串并用它来测试你的代码，以确保字符串是相同的。这是一个例子。如果你想找到：

HOST Address:1.1.1.1:PORT:443

    server tcp

    server 1.1.1.1:443 name myname1

然后通过以下方式与您的搜索字符串进行比较：

test_string = # the string I posted above, you should probably 
              # grab this from a file for consistency. 
kkk = '1.1.1.1:443:myname'
ip, port, name = re.split(":|,", kkk)
assert ip == '1.1.1.1'
assert port == '443' 
assert name == 'myname'
stringNeedsToBeDeleted = getStringInFormat(ip, port, name)
assert stringNeedsToBeDeleted == test_string, "Error, strings are not equal!"

这应该可以为您提供实际问题的线索。我直接从您的示例中抓取的myname1与您的匹配字符串不匹配。

Answer 2

您可以将文件的内容复制到列表中，写入旧文件，改变列表，然后将列表写入文件。

import argparse
import re
import string

p = argparse.ArgumentParser()
p.add_argument("input", help="input the data in format ip:port:name",nargs='*')  
args = p.parse_args()
kkk_list = args.input # ['1.1.1.1:443:myname', '2.2.2.2:443:yourname']


def getStringInFormat(ip, port, name):
     formattedText = "HOST Address:{ip}:PORT:{port}\n"\
                "   server tcp\n"\
                "   server {ip}:{port} name {name}\n\n".format(ip=ip, 
                                                            port=port, 
                                                          name=name)

     return formattedText

with open("file.txt", "r+") as f:
    for kkk in kkk_list:
        ip, port, name = re.split(":|,", kkk)

        stringNeedsToBeDeleted = getStringInFormat(ip, port, name)
        fileContent = fileContent.replace(stringNeedsToBeDeleted, "")

        f.write(fileContent) #now, your file contains all the host addressed and IPs


f = open("file.txt").readlines()

contents = [i.strip('\n').split() for i in f]
new_file = open('file.txt', 'w')
new_file.write('')

new_file.write(''.join(contents[0]))
new_file.write('\n\n\n')
new_file.write(contents[''.join(len(contents)-1])))

new_file.close()

python替换文件中的行没有任何东西

2 个答案: