After the operations you performed, you'll see:
>>> req.headers['content-type']
'text/html; charset=windows-1251'
and so:
>>> encoding=req.headers['content-type'].split('charset=')[-1]
>>> ucontent = unicode(content, encoding)
ucontent
is now a Unicode string (of 140655 characters) -- so for example to display a part of it, if your terminal is UTF-8:
>>> print ucontent[76:110].encode('utf-8')
<title>Lenta.ru: Главное: </title>
and you can search, etc, etc.
Edit: Unicode I/O is usually tricky (this may be what's holding up the original asker) but I'm going to bypass the difficult problem of inputting Unicode strings to an interactive Python interpreter (completely unrelated to the original question) to show how, once a Unicode string IS correctly input (I'm doing it by codepoints -- goofy but not tricky;-), search is absolutely a no-brainer (and thus hopefully the original question has been thoroughly answered). Again assuming a UTF-8 terminal:
>>> x=u'u0413u043bu0430u0432u043du043eu0435'
>>> print x.encode('utf-8')
Главное
>>> x in ucontent
True
>>> ucontent.find(x)
93
Note: Keep in mind that this method may not work for all sites, since some sites only specify character encoding inside the served documents (using http-equiv meta tags, for example).
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…