urllib2 read to Unicode

I need to store the content of a site that can be in any language. And I need to be able to search the content for a Unicode string.

I have tried something like:

import urllib2

req = urllib2.urlopen('http://lenta.ru')
content = req.read()

The content is a byte stream, so I can search it for a Unicode string.

I need some way that when I do urlopen and then read to use the charset from the headers to decode the content and encode it into UTF-8.