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 ：http://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
soup = BeautifulSoup(' Extremely bold ')
tag = soup.b
type(tag)
#
属性可以使用attr拿到，结果是字典
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 bold
del tag['class']
del tag['id']
tag
#
Extremely bold
tag['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 story
The Dormouse's story
Once upon a time there were three little sisters; and their names were
Elsie
,
Lacie
and
Tillie
;
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 story
soup.title
#
soup.body.b
#
The Dormouse's story
soup.a
#
Elsie
soup.find_all('a')
# [
Elsie
,
#
Lacie
,
#
Tillie
]
head_tag = soup.head
head_tag
#
The Dormouse's story
head_tag.contents
[
]
title_tag = head_tag.contents[0]
title_tag
#
title_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
# [
]
for child in head_tag.descendants:
print(child)
#
# The Dormouse's story
len(list(soup.children))
# 1
len(list(soup.descendants))
# 25
title_tag.string
# u'The Dormouse's story'
