text: import paramiko
  import os
  
  
  # open a transport
  transport = paramiko.Transport(('localhost', 3373))
  
  # password auth
  #transport.connect(username='wengyan', password='123456')
  
  # public key auth
  key = paramiko.RSAKey.from_private_key_file('client_dir/clientKeys/wengyan_rsa')
  transport.connect(username='wengyan', pkey=key)
  
  # fork stfp client
  sftp = paramiko.SFTPClient.from_transport(transport)
  
  # list remote server dir
  out=sftp.listdir('.')
  print(out)
  
  # download
  server_path = "server_test1.txt"
  client_path = "client_dir/from_server_test1.txt"
  sftp.get(server_path, client_path)
  
  # upload
  #server_path = "/from_client_test1.txt"
  #client_path = "/Users/wengyan/Dev/gto/github/gto/python/sftp/client_dir/client_test1.txt"
  #sftp.put(client_path, server_path)
  
  
  # Close
  sftp.close()
  transport.close()