Python中处理文件内容的正确姿势该怎样？
大神们：
我想把 htm 文件中的第一个<link 到第二个<link 之间的所有内容另存为一个 htm 该怎么写比较简洁。
<meta http-equiv=“X-UA-Compatible” content=“IE=edge”>
<link rel=“prefetch” href=“https://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js”>
<meta name=“application-name” content=“Python.org”>
<meta name=“msapplication-tooltip” content=“The official home of the Python Programming Language”>
<meta name=“apple-mobile-web-app-title” content=“Python.org”>
<meta name=“apple-mobile-web-app-capable” content=“yes”>
<meta name=“apple-mobile-web-app-status-bar-style” content=“black”>
<meta name=“viewport” content=“width=device-width, initial-scale=1.0”>
<meta name=“HandheldFriendly” content=“True”>
<meta name=“format-detection” content=“telephone=no”>
<meta http-equiv=“cleartype” content=“on”>
<meta http-equiv=“imagetoolbar” content=“false”>
<script type=“text/javascript” async="" src=“https://ssl.google-analytics.com/ga.js”></script><script src="./Welcome to Python.org_files/modernizr.js.下载"></script><style type=“text/css” adt=“123”></style>
<link href="./Welcome to Python.org_files/style.css" rel=“stylesheet” type=“text/css” title=“default”>
<link href="./Welcome to Python.org_files/mq.css" rel=“stylesheet” type=“text/css” media=“not print, braille, embossed, speech, tty”>
提取的内容应该是：
<link rel=“prefetch” href=“https://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js”>
<meta name=“application-name” content=“Python.org”>
<meta name=“msapplication-tooltip” content=“The official home of the Python Programming Language”>
<meta name=“apple-mobile-web-app-title” content=“Python.org”>
<meta name=“apple-mobile-web-app-capable” content=“yes”>
<meta name=“apple-mobile-web-app-status-bar-style” content=“black”>
<meta name=“viewport” content=“width=device-width, initial-scale=1.0”>
<meta name=“HandheldFriendly” content=“True”>
<meta name=“format-detection” content=“telephone=no”>
<meta http-equiv=“cleartype” content=“on”>
<meta http-equiv=“imagetoolbar” content=“false”>
<script type=“text/javascript” async="" src=“https://ssl.google-analytics.com/ga.js”></script><script src="./Welcome to Python.org_files/modernizr.js.下载"></script><style type=“text/css” adt=“123”></style>
<link
Python中处理文件内容的正确姿势该怎样？
处理文件内容，核心就两点：用 with 语句保证资源释放，选对读写模式。
基础操作：
# 读整个文件
with open('file.txt', 'r', encoding='utf-8') as f:
content = f.read()
# 逐行读取（推荐大文件）
with open('file.txt', 'r', encoding='utf-8') as f:
for line in f:
process(line)
# 写入文件（会覆盖）
with open('output.txt', 'w', encoding='utf-8') as f:
f.write('Hello\nWorld')
# 追加内容
with open('output.txt', 'a', encoding='utf-8') as f:
f.write('\nNew line')
关键细节：
- 编码用
utf-8最稳妥 'r'只读，'w'覆盖写，'a'追加，'r+'读写- 大文件用迭代器逐行处理，别一次性读入内存
实用技巧：
# 读取所有行到列表
with open('file.txt', 'r') as f:
lines = f.readlines()
# 同时读写多个文件
with open('input.txt', 'r') as fin, open('output.txt', 'w') as fout:
for line in fin:
fout.write(line.upper())
记住：with open() as f 是标准写法，手动 close() 容易忘。
