使用python删除指定文件夹及子文件，保留多少

python版本为：2.7

import  os,time,shutil,datetime
def rmdir(deldir,N):
    dellist=os.listdir(deldir)
    deldate= datetime.timedelta(days=N)
    now = datetime.datetime.now()
    for  i  in  dellist:
        os.chdir(deldir)
        ctime = datetime.datetime.fromtimestamp(os.path.getctime(i))
        if ctime < (now - deldate):
            #print ("%s rm  dir :%s" %(now,i))
            if os.path.isfile(i):
                os.remove(i)
            else:
                shutil.rmtree(i)

#Timed C--logs deletion
#Delete the directory at midnight every day and keep the last few days
rmdir('C:\logs\Adf.NumberServer',7)
rmdir('C:\logs\Adf.NumberServer',7)