pyquery 学习

　　pyquery 是python仿照jQuery的严格实现,语法与jQuery几乎完全相同,所以对于学过前端的朋友们可以立马上手,没学过的小朋友也别灰心,我们马上就能了解到pyquery的强大.

1 安装

  pip install pyquery

2 官方文档

http://pyquery.readthedocs.io/

3 学习代码html代码

  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>
  '''

4 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
# 格式化html文本,获取'$对象
doc=pq(html) # doc ---> '$'
#获取html文本下所有的li标签
print(doc('li'))

结果

5 URL初始化

from pyquery import PyQuery as pq
#直接获取网页源码
doc=pq(url='https://www.baidu.com')
title=doc(':submit').attr.value
print(title)

结果

6 文件初始化

from pyquery import PyQuery as pq
#读取文件
doc = pq(filename='demo.html') 
print(doc('li'))

结果

7 基于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)
#找id=container标签下 所有class=list标签下的 所有的li标签 
print(doc('#container .list li'))

结果

8 查找元素

子元素(不找孙子)

(链式寻找,doc($)找到的标签对象可以继续查找)

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)
#先获取所有的class=list 标签
items = doc('.list')
#再获取所有的li标签
lis=items('li')
print(lis)

结果

#获取当前标签的所有子标签
lis=items.children()
print(type(lis))
print(lis)

结果

父元素(不找爷爷)

html = '''
<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>
</html>
'''
from pyquery import PyQuery as pq
doc = pq(html)
items = doc('.list')
#获取当前标签的父级别标签(不取爷爷标签)
container = items.parent()
print(type(container))
print(container)

结果

9 遍历

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)
#寻找class=items-0并且class=active的标签
li = doc('.item-0.active')
print(li)

结果

10 获取文本

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">我们一起high high</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)
#定位到 a标签
a = doc('.item-0.active a')
print(a)
#输出文本使用.text()
print(a.text())

结果

11 获取HTML

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)
#获取对应 标签下的 html数据
print(li.html())

结果

12 DOM操作

addClass、removeClass

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)
#给选定标签删除 class='active'
li.removeClass('active')
print(li)
#给选定标签添加 class='active'
li.addClass('active')
print(li)

结果

attr、css

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)
#添加属性 name=link
li.attr('name', 'link')
print(li)
#添加css font-size=14px
li.css('font-size', '14px')
print(li)

结果

remove

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())
#find 找到指定标签,remove 移除
wrap.find('p').remove()
print(wrap.text())

结果

其他DOM方法

http://pyquery.readthedocs.io/en/latest/api.html

13 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)
# 获取第一个li 标签
li = doc('li:first-child')
print(li)
#获取最后一个li 标签
li = doc('li:last-child')
print(li)
#获取第2个li 标签
li = doc('li:nth-child(2)')
print(li)
#获取索引>2 的li 标签
li = doc('li:gt(2)')
print(li)
#获取偶数 的li标签
li = doc('li:nth-child(2n)')
print(li)
#获取文本包含second的 li标签
li = doc('li:contains(second)')
print(li)

结果

更多CSS选择器可以查看 http://www.w3school.com.cn/css/index.asp