[python] Python return list from function

I have a function that parses a file into a list. I'm trying to return that list so I can use it in other functions.

def splitNet():
    network = []
    for line in open("/home/tom/Dropbox/CN/Python/CW2/network.txt","r").readlines():
        line = line.replace("\r\n", "")
        line = string.split(line, ',')
        line = map(int, line)
        network.append(line)
    return network

When I try to print the list outside of the function (for debugging) I get this error:

NameError: name 'network' is not defined

Is there something simple I am doing wrong or is there a better way to pass variables between functions without using globals?