使用python备份指定目录并删除备份超过一定时长的文件

#!/usr/bin/env python
#-*- coding: utf-8 -*-
""" 
@Project:Py
@author:
@Email: 
@Software: PyCharm
@file: test_rm.py 
@time: 2018/1/17 0017 下午 14:14 
"""

import os
import time

# 备份的指定目录
source = ['/usr/local/src/test1/']
# 备份文件存放路径
target_dir='/home/backup/'
# 备份时长
data = 3
# 备份日志
filebak_log = "/var/log/filebak.log"
# 删除备份文件日志
filerm_log = "/var/log/filerm.log"

def file_bak():
    """备份指定目录下的文件"""
    target=target_dir+time.strftime('%Y%m%d%H%M%S')+'.tar.gz'
    cmd='tar -zcPf %s %s '%(target,' '.join(source))
    if os.system(cmd)==0 :
        with open(filebak_log,'a') as filebak:
            filebak.write('successfull backup to %s \n' % target)

# crontab
# 0 4 * * * /usr/bin/python /root/demooil_bak.py >> /var/log/demooil_bak.py.log 2>&1

def file_rm():
    """删除备份目录下超过一定时长的文件"""
    f = list(os.listdir(target_dir))
    now_time = time.strftime('%Y%m%d%H%M%S')[0:8]
    for i in f:
        if i[15:] == 'tar.gz':
            exit_time = i[0:8]
            update_time = int(exit_time) + data
            if update_time < int(now_time):
                os.remove(target_dir+i)
                with open(filerm_log,'a') as file_log:
                    file_log.write("%s删除备份文件%s \n" % (now_time,i))

if __name__ == '__main__':
    file_bak()
    file_rm()