Web page data and urllib2.urlopen

[Massi]

Hi everyone, I'm using the urllib2 library to get the html source code
of web pages. In general it works great, but I'm having to do with a
financial web site which does not provide the souce code I expect. As
a matter of fact if you try:

import urllib2
res = urllib2.urlopen("http://www.marketwatch.com/story/mondays-
biggest-gaining-and-declining-stocks-2009-07-27")
page = res.read()
print page

you will see that the printed code is very different from the one
given, for example, by mozilla. Since I have really little knowledge
in html I can't even understand if this is a python or html problem.
Can anyone give me some help?
Thanks in advance.