terminating applicaton through python script : I was using Python (Popen  and subprocess modules) to open applications and automate some stuff. But, I do not know how to close using one line command/script. It should not take more than one line. 

e.g. I am using

>>>import subprocess
>>>subprocess.Popen(['c:\\windows\\system32\\notepad.exe','C:\\file1.txt']) 

I want to close this file. What is the process? 

