Web page data and urllib2.urlopen

[Dave Angel]

Piet van Oostrum wrote:
> <snip>
>> DA> If Mozilla had seen a page with this line in an appropriate place, it'd
>> DA> immediately begin loading the other page, at "someotherurl"  But there's no
>> DA> such line.
>>     
>
>   
>> DA> Next, I looked for javascript.  The Mozilla page contains lots of
>> DA> javascript, but there's none in the raw page.  So I can't explain Mozilla's
>> DA> differences that way.
>>     
>
>   
>> DA> I did notice the link to /m/Content/mobile2.css, but I don' t know any way
>> DA> a CSS file could cause the content to change, just the display.
>>     
>
>   
>> DA> All I can guess is that it has something to do with "browser type" or
>> DA> cookies.  And that would make lots of sense if this was a cgi page.  But
>> DA> the URL doesn't look like that, as it doesn't end in pl, py, asp, or any of
>> DA> another dozen special suffixes.
>>     
>
>   
>> DA> Any hints, anybody???
>>     
>
> If you look into the HTML that Firefox gets, there is a lot of
> javascript in it.
>   

But the raw page didn't have any javascript.  So what about that 
original raw page triggered additional stuff to be loaded?
Is it "user agent", as someone else brought out?  And is there somewhere 
I can read more about that aspect of things?  I've mostly built very 
static html pages, where the server yields the same page to everybody.  
And some form stuff, where the  user clicks on a 'submit" button to 
trigger a script that's not shown on the URL line.