How to extract from html page links for javascript, css and img tags?

How to extract from html page links for 开发者_如何转开发javascript, css and img tags ? Do I need to use regular expression or there is already some lightweight library for html parsing ?

HTML5Lib in combination with lxml is what I like to use extract data from HTML documents. It recovers from errors in a similar way to modern browsers so it makes broken html easier to work with.

If you actually want to run js code in web pages (say the link is calculated via a function), you should consider looking at the webkit and jswebkit packages which will let you run javascript in a headless webkit window that can get you dynamically generated content for your python parser to examine.

It's really not hard at all to run js in python via webkit, though expect memory usage on par with running a webkit browser.

BeautifulSoup will do the trick.

import urllib
from BeautifulSoup import BeautifulSoup

sock = urllib.urlopen("http://stackoverflow.com")
soup = BeautifulSoup(sock.read())
sock.close()

img = soup.findAll("img")
script = soup.findAll("script", {"type" : "text/javascript"})
css = soup.findAll("link", {"rel" : "stylesheet"})

HTML is not a language which is parsable by regular expressions. SO don't even try. It will break.

What I typically use is Beautiful Soup which is a parser library especially build for gathering information from potentially invalid markup, exactly like the stuff you will find out there.