clear shell screen

[Shawn Minisall]

Does anyone know how to clear the shell screen completely ?  I tried 
import os and then os.system("clear") was said to have worked in Windows 
XP, but it's just bringing up another window, then it turns black and 
then it closes in within about a second moving the prompt at the 
os.system("clear") line .  I've also tried os.system("cls") with the 
same results.

thx