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Python爬虫【解析库之pyquery】

程序员文章站 2022-05-29 13:29:59
该库跟jQuery的使用方法基本一样 http://pyquery.readthedocs.io/ 官方文档 解析库的安装 初始化 1.字符串初始化 2.URL初始化 3.文件初始化 基本CSS选择器 doc(CSS选择器) 查找元素 子元素 E.children() html = '''

该库跟jquery的使用方法基本一样 

 官方文档

解析库的安装

pip3 install pyquery

初始化

1.字符串初始化

html = '''
<div>
    <ul>
         <li class="item-0">first item</li>
         <li class="item-1"><a href="link2.html">second item</a></li>
         <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
         <li class="item-1 active"><a href="link4.html">fourth item</a></li>
         <li class="item-0"><a href="link5.html">fifth item</a></li>
     </ul>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
print(doc('li'))

2.url初始化

from pyquery import pyquery as pq
doc = pq(url='http://www.baidu.com')
print(doc('head'))

3.文件初始化

from pyquery import pyquery as pq
doc = pq(filename='demo.html')
print(doc('li'))

基本css选择器 doc(css选择器)

html = '''
<div id="container">
    <ul class="list">
         <li class="item-0">first item</li>
         <li class="item-1"><a href="link2.html">second item</a></li>
         <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
         <li class="item-1 active"><a href="link4.html">fourth item</a></li>
         <li class="item-0"><a href="link5.html">fifth item</a></li>
     </ul>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
print(doc('#container .list li'))

查找元素

子元素 e.children()

Python爬虫【解析库之pyquery】
html = '''
<div id="container">
    <ul class="list">
         <li class="item-0">first item</li>
         <li class="item-1"><a href="link2.html">second item</a></li>
         <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
         <li class="item-1 active"><a href="link4.html">fourth item</a></li>
         <li class="item-0"><a href="link5.html">fifth item</a></li>
     </ul>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
items = doc('.list')
print(type(items))
print(items)
lis = items.find('li')
print(type(lis))
print(lis)
"""
<class 'pyquery.pyquery.pyquery'>
<ul class="list">
         <li class="item-0">first item</li>
         <li class="item-1"><a href="link2.html">second item</a></li>
         <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
         <li class="item-1 active"><a href="link4.html">fourth item</a></li>
         <li class="item-0"><a href="link5.html">fifth item</a></li>
     </ul>
 
<class 'pyquery.pyquery.pyquery'>
<li class="item-0">first item</li>
         <li class="item-1"><a href="link2.html">second item</a></li>
         <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
         <li class="item-1 active"><a href="link4.html">fourth item</a></li>
         <li class="item-0"><a href="link5.html">fifth item</a></li>
     
"""
子元素
Python爬虫【解析库之pyquery】
html = '''
<div id="container">
    <ul class="list">
         <li class="item-0">first item</li>
         <li class="item-1"><a href="link2.html">second item</a></li>
         <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
         <li class="item-1 active"><a href="link4.html">fourth item</a></li>
         <li class="item-0"><a href="link5.html">fifth item</a></li>
     </ul>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
items = doc('.list')
lis = items.children()
print(type(lis))
print(lis)
"""
<class 'pyquery.pyquery.pyquery'>
<li class="item-0">first item</li>
         <li class="item-1"><a href="link2.html">second item</a></li>
         <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
         <li class="item-1 active"><a href="link4.html">fourth item</a></li>
         <li class="item-0"><a href="link5.html">fifth item</a></li>
"""
children

父元素 e.parent() e.parents()

Python爬虫【解析库之pyquery】
html = '''
<div id="container">
    <ul class="list">
         <li class="item-0">first item</li>
         <li class="item-1"><a href="link2.html">second item</a></li>
         <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
         <li class="item-1 active"><a href="link4.html">fourth item</a></li>
         <li class="item-0"><a href="link5.html">fifth item</a></li>
     </ul>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
items = doc('.list')
container = items.parent()
print(type(container))
print(container)
"""
<class 'pyquery.pyquery.pyquery'>
<div id="container">
    <ul class="list">
         <li class="item-0">first item</li>
         <li class="item-1"><a href="link2.html">second item</a></li>
         <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
         <li class="item-1 active"><a href="link4.html">fourth item</a></li>
         <li class="item-0"><a href="link5.html">fifth item</a></li>
     </ul>
 </div>"""
parent()
Python爬虫【解析库之pyquery】
html = '''
<div class="wrap">
    <div id="container">
        <ul class="list">
             <li class="item-0">first item</li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
         </ul>
     </div>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
items = doc('.list')
parents = items.parents()
print(type(parents))
print(parents)
"""
<class 'pyquery.pyquery.pyquery'>
<div class="wrap">
    <div id="container">
        <ul class="list">
             <li class="item-0">first item</li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
         </ul>
     </div>
 </div><div id="container">
        <ul class="list">
             <li class="item-0">first item</li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
         </ul>
     </div>
"""
parents()
Python爬虫【解析库之pyquery】
parent = items.parents('.wrap')
print(parent)
"""
<div class="wrap">
    <div id="container">
        <ul class="list">
             <li class="item-0">first item</li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
         </ul>
     </div>
 </div>
"""
parents(css选择)

兄弟元素

Python爬虫【解析库之pyquery】
html = '''
<div class="wrap">
    <div id="container">
        <ul class="list">
             <li class="item-0">first item</li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
         </ul>
     </div>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
li = doc('.list .item-0.active')
print(li.siblings())
"""
<li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-0">first item</li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
"""
view code
Python爬虫【解析库之pyquery】
html = '''
<div class="wrap">
    <div id="container">
        <ul class="list">
             <li class="item-0">first item</li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
         </ul>
     </div>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
li = doc('.list .item-0.active')
print(li.siblings('.active'))
view code

遍历

单个元素

html = '''
<div class="wrap">
    <div id="container">
        <ul class="list">
             <li class="item-0">first item</li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
         </ul>
     </div>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
li = doc('.item-0.active')
print(li)

"""
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
"""

多个元素 doc(xx).items()

html = '''
<div class="wrap">
    <div id="container">
        <ul class="list">
             <li class="item-0">first item</li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
         </ul>
     </div>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
lis = doc('li').items()
print(type(lis))
for li in lis:
    print(li)

"""
<class 'generator'>
<li class="item-0">first item</li>
             
<li class="item-1"><a href="link2.html">second item</a></li>
             
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
             
<li class="item-0"><a href="link5.html">fifth item</a></li>
"""

获取信息

获取属性 e.attr(name) or e.attr.name

html = '''
<div class="wrap">
    <div id="container">
        <ul class="list">
             <li class="item-0">first item</li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
         </ul>
     </div>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
a = doc('.item-0.active a')
print(a)
print(a.attr('href'))
print(a.attr.href)
"""
<a href="link3.html"><span class="bold">third item</span></a>
link3.html
link3.html
"""

获取文本 e.text()

html = '''
<div class="wrap">
    <div id="container">
        <ul class="list">
             <li class="item-0">first item</li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
         </ul>
     </div>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
a = doc('.item-0.active a')
print(a)
print(a.text())
"""
<a href="link3.html"><span class="bold">third item</span></a>
third item
"""

获取html e.html()

Python爬虫【解析库之pyquery】
html = '''
<div class="wrap">
    <div id="container">
        <ul class="list">
             <li class="item-0">first item</li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
         </ul>
     </div>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
li = doc('.item-0.active')
print(li)
print(li.html())
"""
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             
<a href="link3.html"><span class="bold">third item</span></a>
"""
view code

dom操作 

类属性的添加与移除 addclass,removeclass

Python爬虫【解析库之pyquery】
html = '''
<div class="wrap">
    <div id="container">
        <ul class="list">
             <li class="item-0">first item</li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
         </ul>
     </div>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
li = doc('.item-0.active')
print(li)
li.removeclass('active')
print(li)
li.addclass('active')
print(li)
"""
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             
<li class="item-0"><a href="link3.html"><span class="bold">third item</span></a></li>
             
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
"""
addclass removeclass

属性操作 attr, css

Python爬虫【解析库之pyquery】
html = '''
<div class="wrap">
    <div id="container">
        <ul class="list">
             <li class="item-0">first item</li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
         </ul>
     </div>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
li = doc('.item-0.active')
print(li)
li.attr('name', 'link')
print(li)
li.css('font-size', '14px')
print(li)
"""
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             
<li class="item-0 active" name="link"><a href="link3.html"><span class="bold">third item</span></a></li>
             
<li class="item-0 active" name="link" style="font-size: 14px"><a href="link3.html"><span class="bold">third item</span></a></li>
"""
attr, css

删除元素 remove

Python爬虫【解析库之pyquery】
html = '''
<div class="wrap">
    hello, world
    <p>this is a paragraph.</p>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
wrap = doc('.wrap')
print(wrap.text())
wrap.find('p').remove()
print(wrap.text())

"""
hello, world this is a paragraph.
hello, world
"""
remove

其他dom方法 

伪类选择器 

html = '''
<div class="wrap">
    <div id="container">
        <ul class="list">
             <li class="item-0">first item</li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
         </ul>
     </div>
 </div>
'''
from pyquery import pyquery as pq
doc = pq(html)
li = doc('li:first-child')
print(li)
li = doc('li:last-child')
print(li)
li = doc('li:nth-child(2)')
print(li)
li = doc('li:gt(2)')
print(li)
li = doc('li:nth-child(2n)')
print(li)
li = doc('li:contains(second)')
print(li)

"""
<li class="item-0">first item</li>
             
<li class="item-0"><a href="link5.html">fifth item</a></li>
         
<li class="item-1"><a href="link2.html">second item</a></li>
             
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a></li>
         
<li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-1 active"><a href="link4.html">fourth item</a></li>
             
<li class="item-1"><a href="link2.html">second item</a></li>
"""

想更多了解css选择器可以查看