PyQuery
什么是PyQuery
PyQuery是強(qiáng)大又靈活的網(wǎng)頁解析庫。如果熟悉jQuery的語法尉桩，那么PyQuery就是你的絕佳選擇
安裝PyQuery
pip3 install PyQuery
用法講解
初始化
字符串初始化常用在得到網(wǎng)頁源代碼郊闯，然后進(jìn)行解析妻献。
html = """
<div>
<ul>
<li class="item-0">first item</li>
<li class="item-1"><a href="link.html">second item</a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></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'))#這里傳入CSS選擇器，標(biāo)簽選擇器团赁，結(jié)果返回所有l(wèi)i
URL初始化
from pyquery import PyQuery as pq
doc = pq(url='http://www.baidu.com')#使用url初始化
print(doc('head'))#返回html中的head
文件初始化
from qyquery import PyQuery as pq
doc = pq(filename='myhtml.html')
print(doc('li'))
基本的CSS選擇器
html = """
<div id="container">
<ul>
<li class="item-0">first item</li>
<li class="item-1"><a href="link.html">second item</a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></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 .active a'))#查找id=container 下的類名為active的 下的所有a標(biāo)簽育拨，只要有層級嵌套關(guān)系，不是直接父子關(guān)系欢摄。
查找元素
子元素熬丧，查找元素下的子元素
html = """
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link.html">second item</a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></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')#想jQuery一樣，可以用find篩選所有子元素怀挠，無論層級
print(type(lis))
print(lis)
返回結(jié)果:返回值是<class 'pyquery.pyquery.PyQuery'>類型
<class 'pyquery.pyquery.PyQuery'>
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link.html">second item</a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></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="link.html">second item</a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
查找直接子元素
html = """
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link.html">second item</a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></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('.item-0')#可能返回多個
print(items.children())#返回直接子元素
返回值：
<a href="lin3.html"><span class="bold">third item</span></a><a href="link5.html">fifth item</a>
這里返回了2條class="item-0"的li的直接子元素
父元素
html = """
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link.html">second item</a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></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)#返回整個class=list的父節(jié)點(diǎn)--div的內(nèi)容
parents()--返回所有的祖先節(jié)點(diǎn)析蝴。
兄弟節(jié)點(diǎn)
html = """
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link.html">second item</a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></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('.active')
print(items.siblings())#返回class=active的所有兄弟節(jié)點(diǎn)
print(items.siblings('.item-1'))#兄弟節(jié)點(diǎn)+CSS選擇器
*返回結(jié)果:
<li class="item-1"><a href="link.html">second item</a></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="link.html">second item</a></li>
遍歷
- 單個元素-返回的是單個元素那么就不談遍歷了，返回的是PyQuery對象
- 多個元素绿淋，如果返回的是多個元素就用.items()闷畸，那么返回的實(shí)際上是一個生成器，可以用for循環(huán)遍歷
html = """
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link.html">second item</a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></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('.active')
lis = items.siblings().items()
print(type(lis))
for item in lis:#遍歷所有兄弟節(jié)點(diǎn)
print(item)
獲取信息
- 獲取屬性
html = """
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link.html">second item</a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></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)
a = doc('.item-0.active a')
print(a)
print(a.attr('href'))#返回屬性為href的值
print(a.attr.href)#同上
返回結(jié)果：
<a href="lin3.html"><span class="bold">third item</span></a>
lin3.html
lin3.html
- 獲取文本
html = """
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link.html">second item</a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></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)
a = doc('.item-0.active a')
print(a)
print(a.text())#返回a標(biāo)簽中的內(nèi)容
返回結(jié)果：
<a href="lin3.html"><span class="bold">third item</span></a>
third item
- 獲取HTML
html = """
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link.html">second item</a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></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)
a = doc('.item-0.active a')
print(a)
print(a.html())#返回整個a標(biāo)簽的html代碼
返回結(jié)果:
<a href="lin3.html"><span class="bold">third item</span></a>
<span class="bold">third item</span>
DOM操作
- addClass吞滞、removeClass
html = """
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link.html">second item</a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></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)
li = doc('.item-0.active')
print(li)
li.removeClass('active')#刪除這個li的類名active
print(li)
li.addClass('active')#又加上active類名
print(li)
輸出結(jié)果
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></a></li>
<li class="item-0"><a href="lin3.html"><span class="bold">third item</span></a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></a></li>
- 添加或修改attr佑菩、css
html = """
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link.html">second item</a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></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)
li = doc('.item-0.active')
print(li)
li.attr('name','mylink')#因?yàn)闆]有name屬性，所以實(shí)際上添加name屬性，值為mylink
print(li)
li.css('font-size','20px')#添加行內(nèi)style
print(li)
- remove
html = """
<div class="wrap">
hello,lll
<p>This is test</p>
</div>
"""
from pyquery import PyQuery as pq
doc = pq(html)
wrap = doc('.wrap')
print(wrap.text())
wrap.find('p').remove()#刪除p標(biāo)簽
print(wrap.text())
偽類選擇器
html = """
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link.html">second item</a></li>
<li class="item-0 active"><a href="lin3.html"><span class="bold">third item</span></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)
li = doc('li:first-child')#html標(biāo)簽下第一個li
print(li)
li = doc('li:last-child')#html標(biāo)簽下最后一個li
print(li)
li = doc('li:nth-child(2)')#html標(biāo)簽下第二個li
print(li)
li = doc('li:gt(2)')#html標(biāo)簽下大于2的所有l(wèi)i
print(li)
li = doc('li:nth-child(2n)')#html標(biāo)簽下偶數(shù)的li
print(li)
li = doc('li:contains(second)')#html標(biāo)簽下li中的內(nèi)容包含second的li
print(li)
