PyQuery的基本使用详解 0.安装：pip3 install pyquery 1.初始化 2.基本CSS选择器 3.查找元素 4.遍历 5.获取信息 6.DOM操作 7.伪类选择器 官网
1.初始化
1.字符串初始化
# 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'))
2.基本CSS选择器
html = """
<div >
<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'))
3.查找元素
1.子元素
html = """
<div >
<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(items)
# 查询li标签
lis = items.find('li')
print(lis)
# 查询孩子
lis = items.children()
print(type(lis))
print(lis)
# 查询带有'.active'的孩子
lis = items.children('.active')
print(lis)
2.父元素
html = """
<div class='wrap'>
<div >
<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')
print(items)
parents = items.parents()
print(parents)
parent = items.parents('.wrap')
print(parent)
3.兄弟元素
html = """
<div class='wrap'>
<div >
<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 .item-0.active')
print(items)
print(items.siblings())
print(items.siblings('.active'))
4.遍历
html = """
<div class='wrap'>
<div >
<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)
# 单个元素
items = doc('.item-0.active')
print(items)
# 遍历元素
lis = doc('li').items()
print(lis)
# <generator object PyQuery.items at 0x0000000003A84468>
for item in lis:
print(item)
5.获取信息
1.获取属性
html = """
<div class='wrap'>
<div >
<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)
2.获取文本
html = """
<div class='wrap'>
<div >
<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())
3.获取HTML
html = """
<div class='wrap'>
<div >
<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())
6.DOM操作
1.addclass、removeclass
html = """
<div class='wrap'>
<div >
<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)
2. attr、css
html = """
<div class='wrap'>
<div >
<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','apollo')
print(li)
li.css('font-size','14px')
print(li)
3. remove
html = """
<div class='wrap'>
Hello World
<p>This is paragraph</p>
</div>
"""
from pyquery import PyQuery as pq
doc = pq(html)
wrap = doc('.wrap')
print('移除前：',wrap.text())
wrap.find('p').remove()
print('移除后：',wrap.text())
4.其他DOM方法
https://pyquery.readthedocs.io/en/latest/api.html
7.伪类选择器
html = """
<div class='wrap'>
<div >
<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)