<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_namelist():
 """Generate namelist. Either through set CONF.zvm.namelist, or by generate based on smt userid. """

    if CONF.zvm.namelist is not None:
        # namelist length limit should be 64, but there's bug limit to 8
        # will change the limit to 8 once the bug fixed
        if len(CONF.zvm.namelist) <= 8:
            return CONF.zvm.namelist

    # return ''.join(('NL', get_smt_userid().rjust(6, '0')[-6:]))
    # py3 compatible changes
    userid = get_smt_userid()
    return 'NL' + userid.rjust(6, '0')[-6:]