以前讲过利用phantomjs做爬虫抓网页 www.jb51.net/article/55789.htm 是配合选择器做的
利用 beautifulsoup(文档 ：www.crummy.com/software/beautifulsoup/bs4/doc/)这个python模块，可以很轻松的抓取网页内容
# coding=utf-8
import urllib
from bs4 import beautifulsoup
url ='http://www.baidu.com/s'
values ={'wd':'网球'}
encoded_param = urllib.urlencode(values)
full_url = url +'?'+ encoded_param
response = urllib.urlopen(full_url)
soup =beautifulsoup(response)
alinks = soup.find_all('a')
上面可以抓取百度搜出来结果是网球的记录。
beautifulsoup内置了很多非常有用的方法。
几个比较好用的特性：
构造一个node元素
代码如下:
soup = beautifulsoup('
extremely bold
')
tag = soup.b
type(tag)
#
属性可以使用attr拿到，结果是字典
代码如下:
tag.attrs
# {u'class': u'boldest'}
或者直接tag.class取属性也可。
也可以自由操作属性
tag['class'] = 'verybold'
tag['id'] = 1
tag
#extremely bolddel tag['class']
del tag['id']
tag
#extremely boldtag['class']
# keyerror: 'class'
print(tag.get('class'))
# none
还可以随便操作，查找dom元素，比如下面的例子
1.构建一份文档
html_doc = """the dormouse's storythe dormouse's storyonce upon a time there were three little sisters; and their names wereelsie,lacie andtillie;
and they lived at the bottom of a well...."""
from bs4 import beautifulsoup
soup = beautifulsoup(html_doc)
2.各种搞
soup.head
#the dormouse's storysoup.title
#the dormouse's storysoup.body.b
# the dormouse's storysoup.a
# elsiesoup.find_all('a')
# [elsie,
# lacie,
# tillie]
head_tag = soup.head
head_tag
#the dormouse's storyhead_tag.contents
[the dormouse's story]
title_tag = head_tag.contents[0]
title_tag
#the dormouse's storytitle_tag.contents
# [u'the dormouse's story']
len(soup.contents)
# 1
soup.contents[0].name
# u'html'
text = title_tag.contents[0]
text.contents
for child in title_tag.children:
print(child)
head_tag.contents
# [the dormouse's story]
for child in head_tag.descendants:
print(child)
#the dormouse's story# the dormouse's story
len(list(soup.children))
# 1
len(list(soup.descendants))
# 25
title_tag.string
# u'the dormouse's story'