import sys, os, ftplib, socket

 CONST_HOST = "FTP服务器地址"

 CONST_USERNAME = "FTP用户名"

 CONST_PWD = "FTP密码"

 CONST_BUFFER_SIZE = 

 class FtpHelper(object):

     ftp = None

     def __init__(self):

         self.ftp = self.connect()

     def connect(self):

         try:

             ftp = ftplib.FTP(CONST_HOST)

             ftp.login(CONST_USERNAME, CONST_PWD)

             return ftp

         except socket.error, socket.gaierror:

             print("FTP is unavailable,please check the host,username and password!")

             sys.exit()

     def disconnect(self):

         self.ftp.quit()

     def upload(self, ftppath, filepath):

         f = open(filepath, "rb")

         self.ftp.cwd(ftppath)

         file_name = os.path.split(filepath)[-]

         try:

             self.ftp.storbinary('STOR %s'%file_name, f, CONST_BUFFER_SIZE)

         except ftplib.error_perm:

             return False

         return True

     def download(self, ftppath, filename):

         f = open(filename, "wb").write

         self.ftp.cwd(ftppath)

         try:

             self.ftp.retrbinary("RETR %s"%filename, f, CONST_BUFFER_SIZE)

         except ftplib.error_perm:

             return False

         return True

     def list(self):

         self.ftp.dir()

     def find(self, ftppath, filename):

         self.ftp.cwd(ftppath)

         ftp_f_list = self.ftp.nlst()

         if filename in ftp_f_list:

             return True

         else:

             return False

 if __name__ == "__main__":

     fh = FtpHelper()

     fh.list()