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。

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)

这是来自@Lother的答案的一个“分叉”(我相信这应该被认为是正确的答案)。

对于这样的文件:

$ cat file.txt 
1: october rust
2: november rain
3: december snow

Lother解决方案中的这个分支工作得很好:

#!/usr/bin/python3.4

with open("file.txt","r+") as f:
    new_f = f.readlines()
    f.seek(0)
    for line in new_f:
        if "snow" not in line:
            f.write(line)
    f.truncate()

改进:

使用open，丢弃了f.s close()的用法 更清晰的if/else用于计算当前行中是否存在字符串

您可以使用re库

假设您能够加载完整的txt文件。然后定义一个不需要的昵称列表，然后用空字符串“”替换它们。

# Delete unwanted characters
import re

# Read, then decode for py2 compat.
path_to_file = 'data/nicknames.txt'
text = open(path_to_file, 'rb').read().decode(encoding='utf-8')

# Define unwanted nicknames and substitute them
unwanted_nickname_list = ['SourDough']
text = re.sub("|".join(unwanted_nickname_list), "", text)

按行号删除文件中的某一行。

用文件名和要删除的行号替换变量filename和line_to_delete。

filename = 'foo.txt'
line_to_delete = 3
initial_line = 1
file_lines = {}

with open(filename) as f:
    content = f.readlines() 

for line in content:
    file_lines[initial_line] = line.strip()
    initial_line += 1

f = open(filename, "w")
for line_number, line_content in file_lines.items():
    if line_number != line_to_delete:
        f.write('{}\n'.format(line_content))

f.close()
print('Deleted line: {}'.format(line_to_delete))

示例输出:

Deleted line: 3

我喜欢这个使用fileinput和inplace方法的方法:

import fileinput
for line in fileinput.input(fname, inplace =1):
    line = line.strip()
    if not 'UnwantedWord' in line:
        print(line)

它比其他答案少一点啰嗦而且足够快