如何提取"br"之前的文字？

Question

我有一个小问题。我正在使用 python 2.7.8。我正在尝试提取应该在 <br> 之前的文本。我喜欢：

<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>1. C99 standard guarantees uniqueness of ____ characters for internal names.<br>
a) 31<br>
b) 63<br>
c) 12<br>
d) 14</p>
<p> more </p>
<p>2. C99 standard guarantess uniqueness of _____ characters for external names.<br>
a) 31<br>
b) 6<br>
c) 12<br>
d) 14</p>
 </div>
</body>
</html>

我尝试过的代码目前在 <br> 之后，而不是在 br.Here 之前，代码是：

from BeautifulSoup import BeautifulSoup, NavigableString, Tag
soup2 = BeautifulSoup(htmls)

for br2 in soup2.findAll('br'):
    next = br2.previousSibling
    if not (next and isinstance(next,NavigableString)):
        continue
    next2 = next.previousSibling
    if next2 and isinstance(next2,Tag) and next2.name == 'br':
        text = str(next).strip()
        if text:

            print "Found:", next.encode('utf-8')

输出结果是：

Found: 
a) 31
Found: 
b) 63
Found: 
c) 12
Found:
d) 14 
a) 31
Found: 
b) 6
Found: 
c) 12
Found:
d) 14 
Found:

知道我哪里做错了吗。

Answer 1

首先，我会改用 BeautifulSoup version 4。 BeautifulSoup3已经很老了，不再维护了：

Beautiful Soup 3 has been replaced by Beautiful Soup 4.

Beautiful Soup 3 only works on Python 2.x, but Beautiful Soup 4 also works on Python 3.x. Beautiful Soup 4 is faster, has more features, and works with third-party parsers like lxml and html5lib. Once the beta period is over, you should use Beautiful Soup 4 for all new projects.

运行:

pip install beautifulsoup4

并更改您的导入语句：

from BeautifulSoup import BeautifulSoup

至：

from bs4 import BeautifulSoup

现在，我要做的是找到问题文本和 get the following br siblings。对于每个兄弟姐妹，得到 next_sibling 这将是答案选项。工作代码：

soup = BeautifulSoup(data, "html5lib")  # using "html5lib" parser here

for question in soup.find_all(text=re.compile(r"^\d+\.")):
    answers = [br.next_sibling.strip() for br in question.find_next_siblings("br")]

    print(question)
    print(answers)
    print("------")

对于问题中提供的示例 HTML，它打印：

1. C99 standard guarantees uniqueness of ____ characters for internal names.
[u'a) 31', u'b) 63', u'c) 12', u'd) 14']
------
2. C99 standard guarantess uniqueness of _____ characters for external names.
[u'a) 31', u'b) 6', u'c) 12', u'd) 14']
------

请注意，您可能需要安装 html5lib library:

pip install html5lib

如何提取"br"之前的文字？

How to extract text before "br"?

html

python

beautifulsoup

html-parsing