Python 正则表达式 - 解析 HTML

Question

I have this little code and it's giving me AttributeError: 'NoneType' object has no attribute 'group'.

import sys
import re

#def extract_names(filename):

f = open('name.html', 'r')
text = f.read()

match = re.search (r'<hgroup><h1>(\w+)</h1>', text)
second = re.search (r'<li class="hover">Employees: <b>(\d+,\d+)</b></li>', text)  

outf = open('details.txt', 'a')
outf.write(match)
outf.close()

My intention is to read a .HTML file looking for the <h1> tag value and the number of employees and append them to a file. But for some reason I can't seem to get it right. Your help is greatly appreciated.

Answer 1

You are using a regular expression, but matching XML with such expressions gets too complicated, too fast. Don't do that.

Use a HTML parser instead, Python has several to choose from:

• ElementTree is part of the standard library
• BeautifulSoup is a popular 3rd party library
• lxml is a fast and feature-rich C-based library.

The latter two handle malformed HTML quite gracefully as well, making decent sense of many a botched website.

ElementTree example:

from xml.etree import ElementTree

tree = ElementTree.parse('filename.html')
for elem in tree.findall('h1'):
    print ElementTree.tostring(elem)

Answer 2

只是为了完成：您的错误消息只是表明您的正则表达式失败并且没有返回任何内容......