第一次用Python語言寫的程式，功能可以基本實現，還有很多不足的地方，需要改進。

#!/usr/local/env python
#-*- coding:UTF-8 -*-

import ftplib
import os
import socket

#HOST='192.168.203.100'
DIRN='/home/ftpadmin'
FILE='test.txt'
def download(f):
    try:
        f.cwd(DIRN)
    except ftplib.error_perm:
        print 'ERROR:Cannot CD to %s ' % DIRN
        f.quit()
        return
    file=raw_input("請選擇要下載的檔案:")
    try:
        f.retrlines('RETR %s' % file,open(file,'wb').write)
    except ftplib.error_perm:
        print 'ERROR:cannot read file %s' % file
        os.unlink(file)
    else:
        print "***Download %s tp CWD " % file
        return
def put(f):
    filepath=raw_input("請輸入要上傳的檔名:")
    f1=open(filepath,'rb')
    file_name=os.path.split(filepath)[-1]
    try:
        f.storlines('STOR %s' % file_name,f1)
    except ftplib.error_perm:
        f.quit()
        return
def show(f):
    f.dir()
def quit1(f):
    print "退出程式"
    f.quit()

order={'d':download,'p':put,'s':show}
def main():
    HOST=raw_input( "請輸入要登入的伺服器地址：")
    try:
        f=ftplib.FTP(HOST)
    except (socket.error,socket.gaierror),e:
        print "ERROR:cannot reache %s" % HOST
        return
    print "...connected to host %s " % HOST
    try:
        f.login('ftpadmin','12345')
    except ftplib.error_perm:
        print 'ERROR:cannot login FTP'
        f.quit()
        return
    print "成功登陸FTP伺服器"
    print "請選擇操作的服務"
    showmenu(f)

def showmenu(f):
    s="""
    (D)ownload
    (P)put
    (s)how 
    (Q)uit
    Enter choice:
    """
    done=False
    while not done:
        chosen=False
        while not chosen:
            try:
                choice=raw_input(s).strip()[0].lower()
            except (EOFError,KeyboardInterrupt):
                print "異常，退出伺服器"
                choice='q'
            print "你的選擇是:%s" % choice
            if choice not in 'dpqs':
                print "invaid option,try again"
            else:
                chosen=True
        if choice=='q':
            quit1(f)
            break
        order[choice](f)
if __name__=='__main__':
    main()