1.网页解析器：从网页中提取有价值的数据。
2.python网页解析的方式：
正则表达式、html.parser（python自带）、Beautiful Soup（第三方）、lxml（python自带）.
Beautiful Soup可以使用html.parser或者lxml作为解析器
3.网页解析器就是结构化解析-DOM（Document Object Model）树
4.安装Beautiful Soup以及官网地址
pip install beautifulsoup4
http://www.crummy.com/software/BeautifulSoup/bs4/doc/
举例说明：
<a href=‘123.html‘ class=‘article_link‘>Python </a> 节点名称：a 节点属性：href=‘123.html‘和class=‘article_link‘ 节点内容：Python
代码实现：
#-*- coding: utf-8 -*-
from bs4 import BeautifulSoup
import re
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>
"""
# 根据HTML网页字符串创建BeautifulSoup
# HTML文档字符串 #HTML解析器 #HTML文档的编码
soup = BeautifulSoup(html_doc,‘html.parser‘,from_encoding=‘utf-8‘)
print (‘-------获取所有的连接------------‘)
links = soup.find_all(‘a‘)
for link in links:
print link.name, link[‘href‘], link.get_text()
print (‘-------获取lacie的连接------------‘)
link_nodes = soup.find_all(‘a‘, href=‘http://example.com/lacie‘)
for link_node in link_nodes:
print link_node.name, link_node[‘href‘], link_node.get_text()
print (‘---------正则匹配----------‘)
link_nodes = soup.find_all(‘a‘, href=re.compile(r"ill"))
for link_node in link_nodes:
print link_node.name, link_node[‘href‘], link_node.get_text()
print (‘---------获取P段落文字----------‘)
p_nodes = soup.find_all(‘p‘, class_="title")
# class_是为避免与关键字冲突
for p_node in p_nodes:
print p_node.name, p_node.get_text()
时间： 2024-10-18 08:18:13