string questions

[Shawn Minisall]

Hi everyone, I'm a beginning programming student in Python and have a 
few questions regarding strings.

If s1 = "spam"

If s2 = "ni!"

1. Would string.ljust(string.upper(s2),4) * 3 start it at the left 
margin and move it 12 spaces to the right because of the 4 *3?  If so, 
why is it in the parathesis for the upper command and not the ljust?   I 
already know that it would cap it to NI!

2.  To get the output "Spam Ni! Spam Ni! Spam Ni!" I could do something 
like this string.join ([s1, s2]),

But I'm a little lost how to get it repeated three times on one line.  
Would I  just have to put the same command on the next two lines?

3. To change spam to spm, the string.replace seems to be the best 
function to use.  However, when I use
string.replace(s1, "a", " ") in python to replace a with an empty space, 
it doesn't work...I just get spam back when I print s1.   Any ideas?

Thanks.

-Shawn