python3使用paramiko操作远程机器

def connect(host,username,password):
    ssh = paramiko.SSHClient()
    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    try:
        ssh.connect(host,username=username,password=password,allow_agent=True)
        return ssh
    except:
        return None

def exec_commands(conn,cmd):
    stdin,stdout,stderr = conn.exec_command(cmd)
    results=stdout.read()+stderr.read()
    print(results)
    return results

def ftpssh(frompath,topath,method="get"):
    t = paramiko.Transport(远程机器IP)
    t.connect(username= 远程机器登录用户名, password = 远程机器登录密码)
    sftp = paramiko.SFTPClient.from_transport(t)
    if method == "get":#将远程文件copy到本地
        sftp.get(frompath, topath)
    elif method == "put":#将本地文件copy到远程机器上
        sftp.put(frompath, topath)
    t.close()