mac系统下的文件备份，为啥老是返回失败呢是需要像windows一样先安装什么东西吗

import os
import time

source=['/Users/F.Florent/origin']

target_dir='/Users/F.Florent/backup'

target=target_dir+os.sep+time.strftime('%Y%m%d%H%M%S')+ '.zip'

if not os.path.exists(target_dir):
    os.mkdir(target_dir)

zip_command='zip-r{0}{1}'.format(target,' '.join(source))

print('Zip command is')
print(zip_command)
print('Running:')
if os.system(zip_command)==0:
    print('Successful backup to',target)
else:
    print('Backup FAILED')

下面是结果
Zip command is
zip-r/Users/F.Florent/backup/20181204155428.zip/Users/F.Florent/origin
Running:
Backup FAILED