Shell Programming and Scripting

#!/usr/bin/env python
import ftplib,datetime,time
today = datetime.date.today()

server="localhost"
user="anonymous"
password="test@hotmail.com"
filelist=[]
months={
 "Jan":"01","Feb":"02","Mar":"03","Apr":"04","May":"05", 
 "Jun":"06","Jul":"07","Aug":"08","Sep":"09","Oct":"10",
 "Nov":"11","Dec":"12"
}

def download(ftp, filename):    
    '''function to download file'''
    ftp.retrbinary("RETR " + filename, open(filename,"wb").write)
    
try:
    ftp = ftplib.FTP()
    ftp.connect(server,21)    
    ftp.login(user,password)
except Exception,e:
    print e
else:    
    ftp.cwd("incoming")    
    ftp.retrlines('LIST',filelist.append)    
    for items in filelist:
        items=items.split()
        mth,day,yr = items[5:8]        
        if ":" in yr:
            yr=today.year        
        thedate = datetime.date(int(yr),int(months[mth]),int(day))
        result = today - thedate 
        if  result.days > 20:
            filename =''.join(items[8:])
            print "downloading .. " , filename
            download(ftp,filename)