How do I get stdout directly into a Python variable

[David Lees]

I am playing with a Python script that issues system commands on linux
and I want the stdout to go directly into a Python variable.  Right now
I am writing to a temp file and then opening it up.  This seems like a
hack.

I am doing something like this:

os.system('diff file1 file2 | wc > temp')
fh = open('temp','r')
line = fh.read()
fh.close()

I see examples of redirecting stdout in texts, but this still creates a
file that needs to be opened.

Thanks in advance.

David Lees