how to get output from system call into data object

[Stephen M. Shelly]

I am still VERY new to python, and I have a pretty ugly logical 
problem to solve. I have tried using perl, but it is very nasty 
looking when I try to use multi-dimensional arrays. I need to run
a command which will return data in column format, I want to extract 
particular columns into data structures that I can then manipulate.
I currently have:
import os
system("my_command | awk {'print $What $I $ Need'}")
 i would like to fill a list of objects with this output, but I 
do not know how......

I know this is not what I should be doing, but I do not have a 
good enough understanding of python to figure out how to create 
my list of data objects 
from this output.

is it like:
MyList = system("Command | awk {print what i need}") ??????????

As always, any and all assistance is rewarded in the afterlife as 
well as with my deepest gratitude.
PEACE