BeautifulSoup
视频地址：
链接: https://pan.baidu.com/s/1rOwBJQ3DDbzT4id9hZe-VQ 密码: mynx
解析库
| 解析器 | 使用方法 | 优势 | 劣势 |
|---|---|---|---|
| Python标准库 | BeautifulSoup(markup, "html.parser") | Python的内置标准库、执行速度适中 、文档容错能力强 | Python 2.7.3 or 3.2.2)前的版本中文容错能力差 |
| lxml HTML 解析器 | BeautifulSoup(markup, "lxml") | 速度快、文档容错能力强 | 需要安装C语言库 |
| lxml XML 解析器 | BeautifulSoup(markup, "xml") | 速度快、唯一支持XML的解析器 | 需要安装C语言库 |
| html5lib | BeautifulSoup(markup, "html5lib") | 最好的容错性、以浏览器的方式解析文档、生成HTML5格式的文档 | 速度慢、不依赖外部扩展 |
基本使用
html = """
The Dormouse's story
The Dormouse's story
Once upon a time there were three little sisters; and their names were
,
Lacie and
Tillie;
and they lived at the bottom of a well.
...
"""
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.prettify())
print(soup.title.string)
The Dormouse's story
The Dormouse's story
Once upon a time there were three little sisters; and their names were
,
Lacie
and
Tillie
;
and they lived at the bottom of a well.
...
The Dormouse's story
标签选择器
选择元素
html = """
The Dormouse's story
The Dormouse's story
Once upon a time there were three little sisters; and their names were
,
Lacie and
Tillie;
and they lived at the bottom of a well.
...
"""
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.title)
print(type(soup.title))
print(soup.head)
print(soup.p)
The Dormouse's story
The Dormouse's story
The Dormouse's story
获取名称
html = """
The Dormouse's story
The Dormouse's story
Once upon a time there were three little sisters; and their names were
,
Lacie and
Tillie;
and they lived at the bottom of a well.
...
"""
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.title.name)
title
获取属性
html = """
The Dormouse's story
The Dormouse's story
Once upon a time there were three little sisters; and their names were
,
Lacie and
Tillie;
and they lived at the bottom of a well.
...
"""
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.p.attrs['name'])
print(soup.p['name'])
dromouse
dromouse
获取内容
html = """
The Dormouse's story
The Dormouse's story
Once upon a time there were three little sisters; and their names were
,
Lacie and
Tillie;
and they lived at the bottom of a well.
...
"""
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.p.string)
The Dormouse's story
嵌套选择
html = """
The Dormouse's story
The Dormouse's story
Once upon a time there were three little sisters; and their names were
,
Lacie and
Tillie;
and they lived at the bottom of a well.
...
"""
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.head.title.string)
The Dormouse's story
子节点和子孙节点
html = """
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.
...
"""
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.p.contents)
['\n Once upon a time there were three little sisters; and their names were\n ',
Elsie
, '\n', Lacie, ' \n and\n ', Tillie, '\n and they lived at the bottom of a well.\n ']
html = """
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.
...
"""
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.p.children)
for i, child in enumerate(soup.p.children):
print(i, child)
0
Once upon a time there were three little sisters; and their names were
1
Elsie
2
3 Lacie
4
and
5 Tillie
6
and they lived at the bottom of a well.
html = """
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.
...
"""
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.p.descendants)
for i, child in enumerate(soup.p.descendants):
print(i, child)
0
Once upon a time there were three little sisters; and their names were
1
Elsie
2
3 Elsie
4 Elsie
5
6
7 Lacie
8 Lacie
9
and
10 Tillie
11 Tillie
12
and they lived at the bottom of a well.
父节点和祖先节点
html = """
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.
...
"""
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.a.parent)
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.
html = """
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.
...
"""
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(list(enumerate(soup.a.parents)))
[(0,
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.
), (1,
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.
...
), (2,
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.
...
), (3,
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.
...
)]
兄弟节点
html = """
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.
...
"""
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(list(enumerate(soup.a.next_siblings)))
print(list(enumerate(soup.a.previous_siblings)))
[(0, '\n'), (1, Lacie), (2, ' \n and\n '), (3, Tillie), (4, '\n and they lived at the bottom of a well.\n ')]
[(0, '\n Once upon a time there were three little sisters; and their names were\n ')]
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
html='''
Hello
- Foo
- Bar
- Jay
- Foo
- Bar
'''
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.find_all('ul'))
print(type(soup.find_all('ul')[0]))
[
- Foo
- Bar
- Jay
,
- Foo
- Bar
]
html='''
Hello
- Foo
- Bar
- Jay
- Foo
- Bar
'''
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
for ul in soup.find_all('ul'):
print(ul.find_all('li'))
[Foo , Bar , Jay ]
[Foo , Bar ]
attrs
html='''
Hello
- Foo
- Bar
- Jay
- Foo
- Bar
'''
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.find_all(attrs={'id': 'list-1'}))
print(soup.find_all(attrs={'name': 'elements'}))
[
- Foo
- Bar
- Jay
]
[
- Foo
- Bar
- Jay
]
html='''
Hello
- Foo
- Bar
- Jay
- Foo
- Bar
'''
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.find_all(id='list-1'))
print(soup.find_all(class_='element'))
[
- Foo
- Bar
- Jay
]
[Foo , Bar , Jay , Foo , Bar ]
text
html='''
Hello
- Foo
- Bar
- Jay
- Foo
- Bar
'''
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.find_all(text='Foo'))
['Foo', 'Foo']
find( name , attrs , recursive , text , **kwargs )
find返回单个元素，find_all返回所有元素
html='''
Hello
- Foo
- Bar
- Jay
- Foo
- Bar
'''
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.find('ul'))
print(type(soup.find('ul')))
print(soup.find('page'))
- Foo
- Bar
- Jay
None
find_parents() find_parent()
find_parents()返回所有祖先节点，find_parent()返回直接父节点。
find_next_siblings() find_next_sibling()
find_next_siblings()返回后面所有兄弟节点，find_next_sibling()返回后面第一个兄弟节点。
find_previous_siblings() find_previous_sibling()
find_previous_siblings()返回前面所有兄弟节点，find_previous_sibling()返回前面第一个兄弟节点。
find_all_next() find_next()
find_all_next()返回节点后所有符合条件的节点, find_next()返回第一个符合条件的节点
find_all_previous() 和 find_previous()
find_all_previous()返回节点后所有符合条件的节点, find_previous()返回第一个符合条件的节点
CSS选择器
通过select()直接传入CSS选择器即可完成选择
html='''
Hello
- Foo
- Bar
- Jay
- Foo
- Bar
'''
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
print(soup.select('.panel .panel-heading'))
print(soup.select('ul li'))
print(soup.select('#list-2 .element'))
print(type(soup.select('ul')[0]))
[
Hello
]
[Foo , Bar , Jay , Foo , Bar ]
[Foo , Bar ]
html='''
Hello
- Foo
- Bar
- Jay
- Foo
- Bar
'''
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
for ul in soup.select('ul'):
print(ul.select('li'))
[Foo , Bar , Jay ]
[Foo , Bar ]
获取属性
html='''
Hello
- Foo
- Bar
- Jay
- Foo
- Bar
'''
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
for ul in soup.select('ul'):
print(ul['id'])
print(ul.attrs['id'])
list-1
list-1
list-2
list-2
获取内容
html='''
Hello
- Foo
- Bar
- Jay
- Foo
- Bar
'''
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, 'lxml')
for li in soup.select('li'):
print(li.get_text())
Foo
Bar
Jay
Foo
Bar
总结
- 推荐使用lxml解析库，必要时使用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选择器熟悉建议使用select()
- 记住常用的获取属性和文本值的方法