Another problem and another way to solve my problem:
Actually I have been a windows ATK user. I have it on windows and I prefer to use it on windows. The problem is this:
I create a script with the ATK on windows and save it as a .py file. Then I want to run this .py file on the ATK on our department cluster and it gives some errors like it doesn't recognize some commands in the .py file. However, the cluster doesn't have any problem with the input files (.py) made by linux version of ATK! So I assumed I have to switch to linux version of ATK on my system. Actually, If I can solve the problem of running .py files made by windows version of ATK on the ATK on the cluster, I wont need to install the linux version. Why the ATK on the cluster cannot run the .py file made by my ATK on windows properly?!
Sorry for the long story!
THANKS