PyQuery庫也是一個非常強大又靈活的網頁解析庫，如果你有前端開發經驗的，都應該接觸過jQuery,那么PyQuery就是你非常絕佳的選擇，PyQuery 是 Python 仿照 jQuery 的嚴格實現。語法與 jQuery 幾乎完全相同，所以不用再去費心去記一些奇怪的方法了。
官網地址：http://pyquery.readthedocs.io/en/latest/
jQuery參考文檔： http://jquery.cuishifeng.cn/
1、字符串的初始化
from pyquery import PyQuery as pq
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>'''
doc = pq(html)
print(doc)
print(type(doc))
print(doc('li'))
<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>
<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>
2、打開html文件
注意路勁問題
from pyquery import PyQuery as pq
doc = pq(filename='index.html')
print(doc)
print(doc('head'))
<title>Title</title>
</head>
<body>
<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>'''
</body>
</html>
<head>
<meta charset="UTF-8"/>
<title>Title</title>
</head>
3、打開某個網站
doc = pq('https://www.baidu.com')
# doc1 = pq(url='https://www.baidu.com')
print(doc)
print(doc('head'))
4、基於CSS選擇器查找
from pyquery import PyQuery as pq
html = '''<div>
<ul id = 'haha'>
<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>'''
doc = pq(html)
print(doc)
#id等於haha下面的class等於item-0下的a標簽下的span標簽（注意層級關系以空格隔開）
print(doc('#haha .item-0 a span'))
<div>
<ul id="haha">
<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>
<span class="bold">third item</span>
5、可以通過已經查找的標簽，查找這個標簽下的子標簽或者父標簽，而不用從頭開始查找。
from pyquery import PyQuery as pq
html = '''<div class=‘content’>
<ul id = 'haha'>
<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>'''
doc = pq(html)
item = doc('div ul')
print(item)
#我們可以通過已經查找到的標簽，再此查找這個標簽下面的標簽
print(item.parent())
print(item.children())
<ul id="haha"> <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 class="‘content’"> <ul id="haha"> <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> <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>
from pyquery import PyQuery as pq
html = '''<div class=‘content’>
<ul id = 'haha'>
<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>'''
doc = pq(html)
item = doc('div ul')
print(item)
#注意這里查找ul標簽的所有子標簽，也就是li標簽，下面是查找class屬性的標簽，如果你把class換成href肯定不行，它指的只是兒子並不是子子孫孫
print(item.children('[class]'))
6、獲取屬性值
from pyquery import PyQuery as pq
html = '''<div class=‘content’>
<ul id = 'haha'>
<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>'''
doc = pq(html)
#注意class=item-0 active是一個class的屬性，但是在pyquery里面要是中間也是空格隔開的話，
#就變成了item-0下的active標簽下的a標簽了，所以這里空格必須改成點
item = doc(".item-0.active a")
print(type(item))
print(item)
#獲取屬性值的兩種方法
print(item.attr.href)
print(item.attr('href'))
<class 'pyquery.pyquery.PyQuery'> <a href="link3.html"><span class="bold">third item</span></a> link3.html link3.html
7、獲取標簽的內容
from pyquery import PyQuery as pq
html = '''<div class=‘content’>
<ul id = 'haha'>
<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>'''
doc = pq(html)
a = doc("a").text()
print(a)
#結果很有趣，他是找到所有標簽的值，然后給連到一起打出來，就像一段話 second item third item fourth item fifth item
8、Dom操作
1、屬性的增加刪除操作
from pyquery import PyQuery as pq
html = '''<div class=‘content’>
<ul id = 'haha'>
<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>'''
doc = pq(html)
li = doc('.item-0.active')
print(li)
#刪除classactive
print(li.removeClass('active'))
#增加class屬性haha
print(li.addClass('haha'))
<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 haha"><a href="link3.html"><span class="bold">third item</span></a></li>
2、attrs和css
注意：下列操作有則改之，無則加之。
from pyquery import PyQuery as pq
html = '''<div class=‘content’>
<ul id = 'haha'>
<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>'''
doc = pq(html)
li = doc('.item-0.active')
print(li)
print(li.attr('id','id_test'))
print(li.css('font-size','20px'))
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li> <li class="item-0 active" id="id_test"><a href="link3.html"><span class="bold">third item</span></a></li> <li class="item-0 active" id="id_test" style="font-size: 20px"><a href="link3.html"><span class="bold">third item</span></a></li>
3、刪除某個標簽，在爬去過程中我們通常爬去一下標簽或者內容下來的時候總會有些不想要的標簽，這個時候我們可以用下面的類似方法刪除這個標簽。
from pyquery import PyQuery as pq
html = '''<div class='content'>
<ul id = 'haha'>
<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>'''
doc = pq(html)
data = doc('.content')
print(data.text())
#刪除所有a標簽
data.find('a').remove()
#再次打印
print(data.text())
first item second item third item fourth item fifth item
first item