python如何在br之后提取文本?

时间:2015-12-09 16:05:03

标签: python html beautifulsoup html-parsing

我正在使用2.7.8并且有点惊讶bcz我得到所有文本但是包含在最后的文本<“br”>没有得到。就像我的html页面:

<html>
<body>
<div class="entry-content" >
<p>Here is a listing of C interview questions on “Variable Names” along with answers, explanations and/or solutions:
</p>

<p>Which of the following is not a valid C variable name?<br>
a) int number;<br>
b) float rate;<br>
c) int variable_count;<br>
d) int $main;</p>   <!--not getting-->

<p> more </p>

<p>Which of the following is true for variable names in C?<br>
a) They can contain alphanumeric characters as well as special characters<br>
b) It is not an error to declare a variable to be one of the keywords(like goto, static)<br>
c) Variable names cannot start with a digit<br>
d) Variable can be of any length</p> <!--not getting -->!

</div>
</body>
</html>

和我的代码:

url = "http://www.sanfoundry.com/c-programming-questions-answers-variable-names-1/"
#url="http://www.sanfoundry.com/c-programming-questions-answers-variable-names-2/"
req = Request(url)
resp = urllib2.urlopen(req)
htmls = resp.read()
from bs4 import BeautifulSoup
soup = BeautifulSoup(htmls)
for br in soup.findAll('br'):
    next = br.nextSibling
    if not (next and isinstance(next,NavigableString)):
        continue
    next2 = next.nextSibling
    if next2 and isinstance(next2,Tag) and next2.name == 'br':
        text = str(next).strip()
        if text:
            print "Found:", next.encode('utf-8')
           # print '...........sfsdsds.............',answ[0].encode('utf-8')   # 

输出:

Found: 
a) int number;
Found: 
b) float rate;
Found: 
c) int variable_count;

Found: 
a) They can contain alphanumeric characters as well as special characters
Found: 
b) It is not an error to declare a variable to be one of the keywords(like goto, static)
Found: 
c) Variable names cannot start with a digit

但是我没有得到最后一个“文本”,例如:

 d) int $main
    and 
 d) Variable can be of any length  

在&lt;“br”&gt;

之后

我想要获得的输出:

Found: 
a) int number;
Found: 
b) float rate;
Found: 
c) int variable_count;
Found:
d) int $main

Found: 
a) They can contain alphanumeric characters as well as special characters
Found: 
b) It is not an error to declare a variable to be one of the keywords(like goto, static)
Found: 
c) Variable names cannot start with a digit
d) Variable can be of any length

2 个答案:

答案 0 :(得分:1)

这是因为BeautifulSoup通过在<br>之前关闭</p>标记将文本强制为有效的xml。美化版本很清楚:

<p>
 Which of the following is not a valid C variable name?
 <br>
  a) int number;
  <br>
   b) float rate;
   <br>
    c) int variable_count;
    <br>
     d) int $main;
    </br>
   </br>
  </br>
 </br>
</p>

因此,d) int $main;文字不是最后<br>代码的兄弟,但是此代码的文字

代码可以是(这里):

...
soup = BeautifulSoup(htmls)
for br in soup.findAll('br'):
    if len(br.contents) > 0:  # avoid errors if a tag is correctly closed as <br/>
        print 'Found', br.contents[0]

它按预期给出:

Found 
a) int number;
Found 
b) float rate;
Found 
c) int variable_count;
Found 
d) int $main;
Found 
a) They can contain alphanumeric characters as well as special characters
Found 
b) It is not an error to declare a variable to be one of the keywords(like goto, static)
Found 
c) Variable names cannot start with a digit
Found 
d) Variable can be of any length

答案 1 :(得分:1)

您可以使用Requests代替urllib2,并通过lxml的html模块提取xml。

from lxml import html
import requests

#request page
page=requests.get("http://www.sanfoundry.com/c-programming-questions-answers-variable-names-1/")

#get content in html format
page_content=html.fromstring(page.content)

#recover all text from <p> elements
items=page_content.xpath('//p/text()')

上面的代码返回<a>元素中包含的文档中所有文本的数组 有了它,您可以简单地索引到数组中以打印您想要的内容。