1. Install
In the command line window, enter the following code download
pip install beautifulsoup4
2. Exercise
>>> import requests
>>> r = requests.get("http://python123.io/ws/demo.html")
>>> r.text
'<html><head><title>This is a python demo page</title></head>\r\n<body>\r\n<p class="title"><b>The demo python introduces several python courses.</b></p>\r\n<p class="course">Python is a wonderful general-purpose programming language. You can learn Python from novice to professional by tracking the following courses:\r\n<a href="http://www.icourse163.org/course/BIT-268001" class="py1" id="link1">Basic Python</a> and <a href="http://www.icourse163.org/course/BIT-1001870001" class="py2" id="link2">Advanced Python</a>.</p>\r\n</body></html>'>>> demo = r.text
>>> from bs4 import BeautifulSoup
>>> soup = BeautifulSoup(demo , "html.parser") #对HTML解析
>>> print(soup.prettify())
<html>
<head>
<title>
This is a python demo page
</title>
</head>
<body>
<p class="title">
<b>
The demo python introduces several python courses.
</b>
</p>
<p class="course">
Python is a wonderful general-purpose programming language. You can learn Python from novice to professional by tracking the following courses:
<a class="py1" href="http://www.icourse163.org/course/BIT-268001" id="link1">
Basic Python
</a>
and
<a class="py2" href="http://www.icourse163.org/course/BIT-1001870001" id="link2">
Advanced Python
</a>
</p>
</body>
</html>
3. Beautiful Soup library is resolved, traverse, Maintenance "label" function library
Beautiful Soup library, also called beautifulsoup4 or bs4
from bs4 import BeautifulSoup
Open file
>>> from bs4 import BeautifulSoup
>>> soup2 = BeautifulSoup(open(“D://demo.html”), "html.parser")
| Parser | Instructions | condition |
| Bs4 HTML parser | BeautifulSoup(mk,’html.parser’) | Installation bs4 library |
| Lxml HTML parser | BeautifulSoup(mk,’lxml’) | pip install lxml |
| Lxml XML parser | BeautifulSoup(mk,’xml’) |
pip install lxml |
| Html5lib parser | BeautifulSoup(mk,’html5lib’) | pip install html5lib |
Beautiful Soup category of basic elements
| fundamental element | Explanation |
| Tag | Tag, the basic information organization unit, respectively <> and </> indicate the beginning and end |
| Name | Name tag, <p> ... </ p> name is 'p', the format: <tag> .name |
| Attributes | Tag attributes, organized in the dictionary, the format: <tag> .attrs |
| NavigableString | Non attribute string in the tag, <> ... </> string in the format: <tag> .string |
| Comment | Note the tag part of the string, a special type Comment |
>>> import requests
>>> r = requests.get("http://python123.io/ws/demo.html")
>>> demo = r.text
>>> from bs4 import BeautifulSoup
>>> soup = BeautifulSoup(demo , "html.parser")
>>> soup.title
<title>This is a python demo page</title>
>>> tag = soup.a
>>> tag
<a class="py1" href="http://www.icourse163.org/course/BIT-268001" id="link1">Basic Python</a>
>>> tag.name
'a'
>>> tag.parent.name
'p'
>>> tag.parent.parent.name
'body'
>>> tag.attrs
{'href': 'http://www.icourse163.org/course/BIT-268001', 'class': ['py1'], 'id': 'link1'}
>>> tag.attrs['class']
['py1']
>>> type(tag.attrs)
<class 'dict'>
>>> type(tag)
<class 'bs4.element.Tag'>
>>> tag.string
'Basic Python'
>>> soup.p
<p class="title"><b>The demo python introduces several python courses.</b></p>
>>> soup.p.string
'The demo python introduces several python courses.'
>>> type(soup.p.string)
<class 'bs4.element.NavigableString'>
