业务场景，异地机房自动拉取已备份好的tar.gz数据库压缩包，并且只保留3天内的压缩包文件，用python实现

#!/usr/bin/env pythonimport requests,time,os,datetime,platformfrom threading import Thread#cd backup dirif platform.system() == 'Windows':    os.chdir('D:\python\mysqlbackup_all')elif platform.system() == 'Linux':    os.chdir('/data/mysqlbackup_all/')#Get 3 days agonow_time = datetime.datetime.now()yes_time = now_time + datetime.timedelta(days=-3)yes_time_3day_ago = yes_time.strftime('%Y%m%d%H%M').replace('30','00')#Get the whole point timeData_time = time.strftime("%Y%m%d%H%M",time.localtime())Data_time_30Minute = Data_time.replace('30','00')#request urldef for_url(url_name):    for i in url_name:          file_url = 'http://186.87.1.98/'+i + '/'+ i + '_aaa_' + '201801311800' +'.tar.gz'        r = requests.get(file_url, stream=True)        with open(i + '_'+Data_time + '.tar.gz', 'wb') as didi:            for chunk in r.iter_content(chunk_size=1024 * 1024):                if chunk:                    didi.write(chunk)        print file_url#delete 3 day ago tar.gz filedef delete_3day(url_name):    for i in url_name:        targat_dir = i + '_' + yes_time_3day_ago + '.tar.gz'        delete_home_ssdb = 'rm %s -rf ' % targat_dir        os.system(delete_home_ssdb)def main():    url_name = ('123', '456', '789', 'aa', 'qq', 'baidu', '163')    t = Thread(target=for_url(url_name),args=url_name)    t.start()    t.join()    delete_3day(url_name)if __name__ == '__main__':     main()