Python regex look-behind requires fixed-width pattern

Question

When trying to extract the title of a html-page I have always used the following regex:

(?<=)([\\s\\S]*)(?=)

<

Answer 1

What about something like:

 r = re.compile("(<title.*>)([\s\S]*)(</title>)")
 title = r.search(page).group(2)

Answer 2

If you just want to get the title tag,

html=urllib2.urlopen("http://somewhere").read()
for item in html.split("</title>"):
    if "<title>" in item:
        print item[ item.find("<title>")+7: ]

Answer 3

Toss out the idea of parsing HTML with regular expressions and use an actual HTML parsing library instead. After a quick search I found this one. It's a much safer way to extract information from an HTML file.

Remember, HTML is not a regular language so regular expressions are fundamentally the wrong tool for extracting information from it.

Answer 4

The regex for extracting the content of non-nested HTML/XML tags is actually very simple:

r = re.compile('<title[^>]*>(.*?)</title>')

However, for anything more complex, you should really use a proper DOM parser like urllib or BeautifulSoup.

Answer 5

Here's a famous answer on parsing html with regular expressions that does a great job of saying, "don't use regex to parse html."