python BeautifulSoup基础知识学习
2016-04-28 10:11
501 查看
之前是想看下scrapy的,但发现其对python3暂不支持,于是转为看看美勺,在网上找了点入门知识,有机会就自己写点小程序。
用例子来学习:
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>
"""
soup=BeautifulSoup(html_doc,"html.parser")
print(soup.title)
print(soup.title.name)
print(soup.title.string)
print(soup.p)
print(soup.a)
print(soup.find_all('a'))
print(soup.find(id='link3'))
print(soup.get_text())
运行后结果:
<title>The Dormouse's story</title>
title
The Dormouse's story
<p class="title"><b>The Dormouse's story</b></p>
<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>
[<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>, <a class="sister" href="http://example.com/lacie" id="link2">Lacie</a>, <a class="sister" href="http://example.com/tillie" id="link3">Tillie</a>]
<a class="sister" href="http://example.com/tillie" id="link3">Tillie</a>
The Dormouse's story
The Dormouse's 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.
...
soup是用BeautifulSoup格式化后的字符串。
使用soup.title得到的是title标签
使用soup.p得到的是<p>标签,但需记住,是文档中的第一个标签,针对其它标签而言,也是如此。如果需要得到所有标签,需要用到find_all()函数,将会得到一个列表,然后我们可以通过列表的相关用法获取到我们所需的东西。
soup.get_text()返回所有的文本信息,如果只针对<p>标签的文本,则可以使用soup.p.get_text()
------------------------------------------------------------------------------------------------------------------------------------------------------
下面具体看下find_all()函数,感觉这个函数比较实用:
soup.find_all(id='link2')
# [<a class="sister" href="http://example.com/lacie" id="link2">Lacie</a>]
soup.find_all(href=re.compile("elsie"))
4000
# [<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>]如果传入的是href,则beautifulsoup将会搜索每个标签中的href
soup.find_all("a", class_="sister")
# [<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>,
# <a class="sister" href="http://example.com/lacie" id="link2">Lacie</a>,
# <a class="sister" href="http://example.com/tillie" id="link3">Tillie</a>]
对于使用类过滤,由于class是python的关键字,所以在过滤的时候,使用class_的方式进行类过滤
----------------------------------------------------
ps:情绪不高,突然不想整理了,还需努力。
用例子来学习:
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>
"""
soup=BeautifulSoup(html_doc,"html.parser")
print(soup.title)
print(soup.title.name)
print(soup.title.string)
print(soup.p)
print(soup.a)
print(soup.find_all('a'))
print(soup.find(id='link3'))
print(soup.get_text())
运行后结果:
<title>The Dormouse's story</title>
title
The Dormouse's story
<p class="title"><b>The Dormouse's story</b></p>
<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>
[<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>, <a class="sister" href="http://example.com/lacie" id="link2">Lacie</a>, <a class="sister" href="http://example.com/tillie" id="link3">Tillie</a>]
<a class="sister" href="http://example.com/tillie" id="link3">Tillie</a>
The Dormouse's story
The Dormouse's 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.
...
soup是用BeautifulSoup格式化后的字符串。
使用soup.title得到的是title标签
使用soup.p得到的是<p>标签,但需记住,是文档中的第一个标签,针对其它标签而言,也是如此。如果需要得到所有标签,需要用到find_all()函数,将会得到一个列表,然后我们可以通过列表的相关用法获取到我们所需的东西。
soup.get_text()返回所有的文本信息,如果只针对<p>标签的文本,则可以使用soup.p.get_text()
------------------------------------------------------------------------------------------------------------------------------------------------------
下面具体看下find_all()函数,感觉这个函数比较实用:
soup.find_all(id='link2')
# [<a class="sister" href="http://example.com/lacie" id="link2">Lacie</a>]
soup.find_all(href=re.compile("elsie"))
4000
# [<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>]如果传入的是href,则beautifulsoup将会搜索每个标签中的href
soup.find_all(href=re.compile("elsie"), id='link1') # [<a class="sister" href="http://example.com/elsie" id="link1">three</a>]指定多个属性,可实现更多过滤
soup.find_all("a", class_="sister")
# [<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>,
# <a class="sister" href="http://example.com/lacie" id="link2">Lacie</a>,
# <a class="sister" href="http://example.com/tillie" id="link3">Tillie</a>]
对于使用类过滤,由于class是python的关键字,所以在过滤的时候,使用class_的方式进行类过滤
----------------------------------------------------
ps:情绪不高,突然不想整理了,还需努力。
相关文章推荐
- python代码加密
- 梯度下降法Python代码
- window安装python,ipython,pycharm
- Python文件操作读写文件
- 初始python
- 给Python初学者的一些技巧
- python中#!/usr/bin/python与#!/usr/bin/env python的区别
- python发邮件
- Python全栈开发之1、输入输出与流程控制
- 如何解决Sublime Text 3不能正确显示中文的问题
- Python 連接 MySQL
- Python3学习(一)-基础、数据类型、变量、字符串和编码、list&tuple、if、for、while、dict、set、函数与参数
- python模拟登录博客园并爬取用户粉丝数
- python3正则表达式符号和用法
- osx xcode 创建python项目
- Python之No module named setuptools 安装pip
- python文件读写小结
- python_笔记12_匿名函数
- python_笔记11_闭包(SSS)
- python简单的算法