绵阳 网站设计,网站建设方案200字,建站教程图解,长沙设计公司排行榜利用它可以不用编写正则表达式即可方便的实现网页信息的提取。
pip3 install beautifulsoup4
用法讲解#xff1a;常用解析库#xff1a;
lxml HTML解析器
lxml XML解析器
from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(soup.prettify()) #格式化代…利用它可以不用编写正则表达式即可方便的实现网页信息的提取。
pip3 install beautifulsoup4
用法讲解常用解析库
lxml HTML解析器
lxml XML解析器
from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(soup.prettify()) #格式化代码
print(soup.title.string)
------------------------------------------------------------------
#标签选择器
##选择元素
from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(soup.title)
print(type(soup.title))
print(soup.head)
print(soup.p)
如果有很多满足条件只会输出第一个。
##获取名称from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(soup.title.name)
##获取属性from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(soup.p.attrs[name])#获取name属性的值
print(soup.p[name])
##获取内容:
from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(soup.p.string)
##嵌套选择
from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(soup.head.title.string)##1、子节点和子孙节点
from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(soup.p.children)#迭代器
for i,child in enumerate(soup.p.children):print(i,child)
##2
from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(soup.p.contents)#获取p内的所有内容列表
##3
from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(soup.p.descendants) #迭代器
for i,child in enumerate(soup.p.descendants):print(i,child)
##1、父节点和祖先节点
from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(soup.p.parent) #迭代器##2
from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(enumerate(list(soup.p.parents))) #迭代器##兄弟节点
from bst import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(list(enumerate(soup.a.next_siblings)))
print(list(enumerate(soup.a.privious_siblings)))
------------------------------------------------------------------
#标准选择器
find_all(name,attrs,recursive,text,**kwargs)
可根据标签名、属性、内容查找文档
##name
from bs4 import BeautifulSoup
soup BeautifulSoup(html,html)
print(soup.find_all(ul))
print(type(soup.find_all(ul)[0]))from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
for ul in soup.find_all(ul):print(ul.find_all(li))##attrs
from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(soup.find_all(attrs{id:list-1}))
print(soup.find_all(attrs {name:element}))
print(soup.find_all(id list-1))
print(soup.find_all(class_element)) ##以上四句的输出一样##text
from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(soup.find_all(textFoo))#find(name,attrs,recursive,text,**kwargs)
返回单个元素.
from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
print(soup.find(ul))
print(type(soup.find(ul)))
print(soup.find(page))#find_parents()find_parent()
find_next_siblings() find_next_sibling()
find_all_next() find_next()
find_all_previous() find_previous()#CSS选择器
通过select()直接传入CSS选择器即可完成选择
from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
pirnt(soup.select(.panel.panel-heading))# class用.
print(soup.select(ul li))
print(soup.select(#list-2.element))
print(type(soup.select(ul)[0]))#from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
for ul in soup.select(ul):print(ul.select(li))
##获取属性from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)for ul in soup.select(ul):print(u[id])print(ul.attrs[id])
##获取内容from bs4 import BeautifulSoup
soup BeautifulSoup(html,lxml)
for ul in soup.select(li):print(li.get_text())#标签选择器
#标准选择器
#CSS选择器
总结* 推荐使用lxml解析库,必要使用html.parser* 标签选择筛选功能弱但是速度快。* 建议使用find()find_all()查询匹配单个结果或者多个结果。* 如果对CSS选择器熟悉可以使用select()* 记住常用的获取属性和文本值的方法。
