python ftp 文件上传和文件下载

import ftplib
import os
import socket

HOST='192.168.30.109'
FILE='test'

def main():
try:
f=ftplib.FTP(HOST)
except (socket.error,socket.gaierror),e:
print 'ERROR:cannot reach "%s"'% HOST
return
print '***connected to host "%s"' % HOST

try:
f.login(user='test',passwd='123')
except ftplib.error_perm:
print 'ERROR:cannot login anonymously'
f.quit()
return
print '***Logged in as "test""'

try:
f.retrbinary('RETR %s' % FILE,open(FILE,'wb').write)
except ftplib.error_perm:
print 'ERROR:cannot read file "%s"' % FILE
os.unlink(FILE)
else:
print '***Downloaded "%s" to CWD' % FILE
return
try:
f.storbinary('STOR %s' % FILE,open(FILE,'rb'))
except ftplib.error_perm:
print 'ERROR:cannot up file "%s"' % FILE
os.unlink(FILE)
else:
print '***upload "%s" to ftp' % FILE
f.quit()
return

if __name__=='__main__':
main()