在Python字符串中剥离某些html标签的最快方法是什么？

Question

I'd like to strip all html / javascript except for:

<b></b>
<ul></ul>
<li></li>
<a></a>

Thanks.

Answer 1

Do you want a way that's fast or a way that's correct? A regex-based approach is unlikely to be correct and may open you up to XSS attacks.

You should use an HTML parser like Beautiful Soup or even htmllib .

Also, <a> can contain javascript: href s and there are also the various on * attributes which are javascript. You probably want to strip all of those out. In general, a whitelist approach is best: only keep attributes (and attribute values) you know are safe.

Answer 2

While I agree with Laurence, there are occasions where a quick and dirty 99% approach gets the job done without creating other problems.

Here's an example that demonstrates a regex based approach --

import re

CLEANBODY_RE = re.compile(r'<(/?)(.+?)>', re.M)

def _repl(match):
    tag = match.group(2).split(' ')[0]
    if tag == 'p':
        return '<%sp>' % match.group(1)
    elif tag in ('a', 'br', 'ul', 'li', 'b', 'strong', 'em', 'i'):
        return match.group(0)
    return u''

def cleanbody(html):
    return CLEANBODY_RE.sub(_repl, html)

Answer 3

将您要保留的元素替换为占位符值，然后对所有剩余的<。*>进行正则表达式，最后将占位符替换为相应的html元素。