라즈베리파이에서 크론탭을 이용한 주기적 백업 질문

import os 
import sys
import datetime
 
base_path = '/mnt/hdd/rasp_backup/'
backup_list = ''
backup_file = ''
backup_list_full = ['/home', '/etc', '/sys', '/lib', '/srv', '/sbin', '/bin', '/var', '/media', '/selinux', '/usr', '/opt']
backup_list_partial = ['/home', '/etc']
 
if datetime.datetime.now().day <= 7 or len(sys.argv) >= 2:
    backup_file = base_path + 'full_' + datetime.datetime.now().strftime('%y%m%d%H%M') + '.tar.gz'
    backup_list = backup_list_full
    os.system('rm -f full_*')
else :
    backup_file = base_path + 'partial_' + datetime.datetime.now().strftime('%y%m%d%H%M') + '.tar.gz'
    backup_list = backup_list_partial
    os.system('rm -f partial_*')
 
os.system('tar cvfz ' + backup_file + ' ' + ' '.join(backup_list))