Python3爬虫入门之pyquery库的使用
2018-03-28 16:48
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pyquery
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')) # CSS选择器<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>
URL初始化
from pyquery import PyQuery as pq
doc = pq(url='http://www.baidu.com')
print(doc('head'))<head><meta http-equiv="content-type" content="text/html;charset=utf-8"/><meta http-equiv="X-UA-Compatible" content="IE=Edge"/><meta content="always" name="referrer"/><link rel="stylesheet" type="text/css" href="http://s1.bdstatic.com/r/www/cache/bdorz/baidu.min.css"/><title>ç™¾åº¦ä¸€ä¸‹ï¼Œä½ å°±çŸ¥é“</title></head>
文件初始化
from pyquery import PyQuery as pq
doc = pq(filename='demo.html')
print(doc('li'))---------------------------------------------------------------------------
FileNotFoundError Traceback (most recent call last)
<ipython-input-2-3bbce00905be> in <module>()
1 from pyquery import PyQuery as pq
----> 2 doc = pq(filename='demo.html')
3 print(doc('li'))
D:\Anaconda3\lib\site-packages\pyquery\pyquery.py in __init__(self, *args, **kwargs)
214 # specific case to get the dom
215 if 'filename' in kwargs:
--> 216 html = open(kwargs['filename'])
217
4000
elif 'url' in kwargs:
218 url = kwargs.pop('url')
FileNotFoundError: [Errno 2] No such file or directory: 'demo.html'基本CSS选择器
‘id’ = ‘#’, ‘class’ = ‘.’, 标签直接写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')) # 'id' = '#', 'class' = '.'
<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>
查找元素
子元素
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>
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>
lis = items.children('.active')
print(lis)<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>
父元素
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>
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>
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>
兄弟元素
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('.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>
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'))
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
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>
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
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
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
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>
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)
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>
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)
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>
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())
wrap.find('p').remove()
print(wrap.text())Hello, World This is a paragraph. Hello, World
其他DOM方法
http://pyquery.readthedocs.io/en/latest/api.html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>
更多CSS选择器可以查看
http://www.w3school.com.cn/css/index.asp
官方文档
http://pyquery.readthedocs.io/
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