text: import os
  import paramiko
  
  host = 'localhosr'
  username = 'root'
  password = '123456'
  
  ssh = paramiko.SSHClient()
  parmiko.util.log_to_file(log_filename)
  ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
  
  try:
      print "creating connection"
      ssh.connect(host, username=username, password=password)
      print "connected"
      yield ssh
  finally:
      print "closing connection"
      ssh.close()
      print "closed"
  