假设我有一个充满昵称的文本文件。如何使用Python从这个文件中删除特定的昵称?


当前回答

将文件行保存在一个列表中,然后从列表中删除要删除的行,并将剩余的行写入一个新文件

with open("file_name.txt", "r") as f:
    lines = f.readlines() 
    lines.remove("Line you want to delete\n")
    with open("new_file.txt", "w") as new_f:
        for line in lines:        
            new_f.write(line)

其他回答

将文件行保存在一个列表中,然后从列表中删除要删除的行,并将剩余的行写入一个新文件

with open("file_name.txt", "r") as f:
    lines = f.readlines() 
    lines.remove("Line you want to delete\n")
    with open("new_file.txt", "w") as new_f:
        for line in lines:        
            new_f.write(line)

下面是其他一些从文件中删除/some行的方法:

src_file = zzzz.txt
f = open(src_file, "r")
contents = f.readlines()
f.close()

contents.pop(idx) # remove the line item from list, by line number, starts from 0

f = open(src_file, "w")
contents = "".join(contents)
f.write(contents)
f.close()

首先,打开文件并从文件中获取所有的行。然后以写模式重新打开文件,写回你想要删除的行:

with open("yourfile.txt", "r") as f:
    lines = f.readlines()
with open("yourfile.txt", "w") as f:
    for line in lines:
        if line.strip("\n") != "nickname_to_delete":
            f.write(line)

您需要去掉比较中的换行符(“\n”),因为如果您的文件不以换行符结束,那么最后一行也不会以换行符结束。

我认为如果你把文件读入一个列表,然后你可以遍历这个列表来寻找你想要去掉的昵称。您可以在不创建额外文件的情况下高效地执行此操作,但必须将结果写回源文件。

以下是我可能的做法:

import, os, csv # and other imports you need
nicknames_to_delete = ['Nick', 'Stephen', 'Mark']

我假设nicknames.csv包含如下数据:

Nick
Maria
James
Chris
Mario
Stephen
Isabella
Ahmed
Julia
Mark
...

然后将文件加载到列表中:

 nicknames = None
 with open("nicknames.csv") as sourceFile:
     nicknames = sourceFile.read().splitlines()

接下来,迭代到list以匹配要删除的输入:

for nick in nicknames_to_delete:
     try:
         if nick in nicknames:
             nicknames.pop(nicknames.index(nick))
         else:
             print(nick + " is not found in the file")
     except ValueError:
         pass

最后,将结果写回文件:

with open("nicknames.csv", "a") as nicknamesFile:
    nicknamesFile.seek(0)
    nicknamesFile.truncate()
    nicknamesWriter = csv.writer(nicknamesFile)
    for name in nicknames:
        nicknamesWriter.writeRow([str(name)])
nicknamesFile.close()

在我看来,最好和最快的选择是在其他地方重写文件,而不是将所有内容存储在一个列表中并重新打开文件来写入。

with open("yourfile.txt", "r") as file_input:
    with open("newfile.txt", "w") as output: 
        for line in file_input:
            if line.strip("\n") != "nickname_to_delete":
                output.write(line)

就是这样!在一个且只有一个循环中,你可以做同样的事情。这样会快得多。