python使用ssh连接到linux服务器执行命令

#### 环境
Win10+Python3使用SSH连接centos7多次执行 删除ocserv用户的命令

1.存储用户名的文件 del_vpn_user.txt，每行一个
```shell
cat del_vpn_user.txt
zhangsan
lisi
```
2.待执行命令格式：ocpasswd -c /etc/ocserv/ocpasswd -d  用户名
3.示例 服务器地址、ssh端口、用户名、密码：host='192.168.1.1', port=22, username='root', pwd='localnetwork'

#### python脚本

```python
#!/usr/bin/env python
# -*- coding:utf-8 -*-
import paramiko

class SSHConnection(object):

def __init__(self, host='192.168.1.1', port=22, username='root', pwd='localnetwork'):
        self.host = host
        self.port = port
        self.username = username
        self.pwd = pwd
        self.__k = None

def run(self):
        errnum = 0  # 容错计数，避免网络不好时偶尔中断错误
        self.connect()  # 连接远程服务器
        #self.upload('db.py','/tmp/1.py')  # 将本地的db.py文件上传到远端服务器的/tmp/目录下并改名为1.py
        self.cmd('date')  # 执行date 命令

## ocpasswd -c /etc/ocserv/ocpasswd -d
        with open('del_vpn_user.txt', 'r', encoding='utf-8') as vf:
            for line in vf.readlines():
                try:
                    vpnuser = line.strip()
                    self.cmd('ocpasswd -c /etc/ocserv/ocpasswd -d {vpnuser}'.format(vpnuser=vpnuser))

except:
                    print("*vpndel" * 88)
                    print(e)
                    print(line)
                    errnum += 1
                    print(errnum)
                    if errnum <= 3:  # 增加3次容错，避免网络不好时偶尔中断错误
                        self.connect()  # 连接远程服务器
                        self.cmd('date')  # 执行date 命令
                        vpnuser = line.strip()
                        self.cmd('ocpasswd -c /etc/ocserv/ocpasswd -d {vpnuser}'.format(vpnuser=vpnuser))

self.close()    # 关闭连接

def connect(self):
        transport = paramiko.Transport((self.host, self.port))
        transport.connect(username=self.username, password=self.pwd)
        self.__transport = transport

def close(self):
        self.__transport.close()

def upload(self,local_path,target_path):
        sftp = paramiko.SFTPClient.from_transport(self.__transport)
        sftp.put(local_path,target_path)

def cmd(self, command):
        ssh = paramiko.SSHClient()
        ssh._transport = self.__transport
        # 执行命令
        print(command)
        stdin, stdout, stderr = ssh.exec_command(command)
        # 获取命令结果
        result = stdout.read()
        print(result)
        return result

obj = SSHConnection()
obj.run()
```