paramiko结果取不到值，

import paramiko


def doshell(hostname, port, username, password, shellcommand):
    ssh = paramiko.SSHClient()
    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    ssh.connect(hostname, port, username, password)
    stdin, stdout, stderr = ssh.exec_command(shellcommand)
    result = stdout.readlines()
    ssh.close()
    return result


def check_disk(hostname, port, username, password):
    shellcommand = '/oracle/check/shell.sh'
    # shellcommand = 'df -h'
    result = doshell(hostname, port, username, password, shellcommand)
    print(result)



def main():

    hostname = '192.168.32.130'
    port = 22
    username = 'oracle'
    password = 'password'
    # doshell(hostname, port, username, password)
    check_disk(hostname, port, username, password)


if __name__ == '__main__':
    main()返回结果
C:\Users\ZXW\AppData\Local\Programs\Python\Python37\python.exe E:/PYTHON/学习用/LiaoXueFeng/test1.py
[]
Process finished with exit code 0
正常执行脚本后，返回结果：
[oracle@oracle check]$ ./shell.sh
['SYSAUX', '600', '515.75', '85.9583333']
['SYSTEM', '750', '741.75', '98.9']
请路过的各位大神帮忙看看，是什么原因，谢谢。