python call external program

[Ben Thomas]

very simple question:

What would I do to have Python execute something from the DOS command
line. I am very new to python but I bet it is in a moudule but don't
know the command or the modules to look in. I want to

dir >%myvar.txt

#this code would run dir from the command line and pass the var "myvar"
, dir would dump a listing of the files into a text file called xxxx.txt




pointers?

Ben