bs4数据解析原理

1. 实例化一个BeautifulSoup对象，并且将页面源码数据加载到该对象中
2. 通过调用BeautifulSoup对象中相关的属性方法进行标签定位和数据提取

如何实例化BeautifulSoup对象：

• from bs4 import BeautifulSoup
• 对象实例化：将本地页面源码加载到BeautifulSoup中:
  • fp=open('./test.html','r',encoding='utf-8')
  • soup=BeautifulSoup(fp,'lxml')
• 对象实例化：将互联网页面源码加载到BeautifulSoup中:
  • page_text=response.text
  • soup=BeautifulSoup(page_text,'lxml')

代码示例

from bs4 import  BeautifulSoup
fp=open('sougou.html','r',encoding='utf-8')
soup=BeautifulSoup(fp,'lxml')
# print(soup.a)              #soup.TagName返回的是html中第一次出现的tagname标签
# print(soup.find('div',class_='single-share'))   #属性定位
# print(soup.find_all('div',class_='single-share'))  #返回所有
print(soup.select('.single-share>a')[0].text)