Beautiful Soup库的安装
1.简介
Beautiful Soup库是解析、遍历、维护“标签树”的功能库。它对应一个HTML/XML文档的全部内容。Beautiful Soup库也叫beautifulsoup4或者bs4。常用引入方法为：
from bs4 import BeautifulSoup2.安装
2.1 以管理员身份运行cmd命令台
2.2 在命令台上执行以下代码：
pip install beautifulsoup4
2.3 测验是否安装成功
import requests
r=requests.get("https://python123.io/ws/demo.html")
demo=r.text
from bs4 import BeautifulSoup #导入类
soup=BeautifulSoup(demo,"html.parser")#对demo进行html的解析
print(soup.prettify())运行结果
<html>
<head>
<title>
This is a python demo page
</title>
</head>
<body>
<p class="title">
<b>
The demo python introduces several python courses.
</b>
</p>
<p class="course">
Python is a wonderful general-purpose programming language. You can learn Python from novice to professional by tracking the following courses:
<a class="py1" href="http://www.icourse163.org/course/BIT-268001" id="link1">
Basic Python
</a>
and
<a class="py2" href="http://www.icourse163.org/course/BIT-1001870001" id="link2">
Advanced Python
</a>
.
</p>
</body>
</html>