get a list of all non-system users on a Mac in Python

getusers.py

def getusers():
    '''get all non-system users on this Mac'''
    cmd = ['dscl', '.', '-list', '/Users']
    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    out, _ = proc.communicate()
    userlist = out.splitlines()
    users = []
    filter_out = ['daemon', 'root', 'nobody']
    for user in userlist:
        if not user.startswith('_') and not user in filter_out:
            users.append(user)
    return users