Beautiful Soup 包：
Beautiful Soup: Python 的第三方插件用来提取 xml 和 HTML 中的数据。官网地址 https://www.crummy.com/software/BeautifulSoup/
1、安装 Beautiful Soup
打开 cmd（命令提示符），进入到 Python（Python2.7版本）安装目录中的 scripts 下，输入 dir 查看是否有 pip*ex.e**, 如果用就可以使用 Python 自带的 pip 命令进行安装，输入以下命令进行安装即可：
pip install beautifulsoup4
2、测试是否安装成功
编写一个 Python 文件，输入:
import bs4
print bs4
运行该文件，如果能够正常输出则安装成功。
五、使用 Beautiful Soup 解析 html 文件
# -*- coding: UTF-8 -*-
import bs4
import re
from bs4 import BeautifulSoup
html_doc = """
<html><head><title>The Dormouse's story</title></head>
<body>
<p class="title"><b>The Dormouse's story</b></p>
<p class="story">Once upon a time there were three little sisters; and their names were
<a href="http://example.com/elsie" class="sister" id="link1">Elsie</a>,
<a href="http://example.com/lacie" class="sister" id="link2">Lacie</a> and
<a href="http://example.com/tillie" class="sister" id="link3">Tillie</a>;
and they lived at the bottom of a well.</p>
<p class="story">...</p>
"""
# 创建一个BeautifulSoup解析对象
soup = BeautifulSoup(html_doc, "html.parser", from_encoding="utf-8")
# 获取所有的链接
links = soup.find_all('a')
print("所有的链接")
for link in links:
print(link.name, link['href'], link.get_text())
print("获取特定的URL地址")
link_node = soup.find('a', href="http://example.com/elsie")
print(link_node.name, link_node['href'], link_node['class'], link_node.get_text())
print("正则表达式匹配")
link_node = soup.find('a', href=re.compile(r"ti"))
print(link_node.name, link_node['href'], link_node['class'], link_node.get_text())
print("获取P段落的文字")
p_node = soup.find('p', class_='story')
print(p_node.name, p_node['class'], p_node.get_text())
===========
输出：
C:\Python3\python*ex.e** D:/python/project/爬虫/testBeautifllSoup.py
C:\Python3\lib\site-packages\bs4\__init__.py:226: UserWarning: You provided Unicode markup but also provided a value for from_encoding. Your from_encoding will be ignored.
warnings.warn("You provided Unicode markup but also provided a value for from_encoding. Your from_encoding will be ignored.")
所有的链接
a http://example.com/elsie Elsie
a http://example.com/lacie Lacie
a http://example.com/tillie Tillie
获取特定的URL地址
a http://example.com/elsie ['sister'] Elsie
正则表达式匹配
a http://example.com/tillie ['sister'] Tillie
获取P段落的文字
p ['story'] Once upon a time there were three little sisters; and their names were
Elsie,
Lacie and
Tillie;
and they lived at the bottom of a well.
进程已结束,退出代码0