折腾了一天的装饰器，貌似理解了其中的一点点．．．

#!/usr/bin/env python3
#coding=utf-8
import getpass
from netmiko import ConnectHandler
from netmiko.ssh_exception import NetMikoTimeoutException,NetMikoAuthenticationException

def auth(Conn):
    def wrapper(ip,username,password):
        device = {
                  'device_type': 'cisco_ios',
                  'ip': ip,
                  'username': username,
                  'password': password,
                }
        try:
            connect = ConnectHandler(**device)
            connect.enable()
        except (EOFError, NetMikoTimeoutException):
            print(u" 网络设备%s:  无法连接!请确认该设备IPAddress是否可达！"%ip)  
            return
        except (EOFError, NetMikoAuthenticationException):
            print(u" 网络设备%s:  用户名与密码错误!请确认账号与密码！" %ip)
            return
        Conn(ip,username,password,connect)    
        return Conn
    return wrapper

@auth
def showInterface(ip,username,password,connect):
    res = connect.send_command('show ip int brief')
    print(res)
    connect.disconnect()

@auth
def showVersion(ip,username,password,connect):
    res = connect.send_command('show version')
    print(res)
    connect.disconnect()
 

def main():
    print(u"选项请输入数字，如: 1、2")
    print(u"1. 查询设备接口信息")
    print(u"2. 查询设备版本信息")
    print("")
    runFunc = int(input(u'请输入需要执行命令的选项: '))
    input_ip   = input("IPAddress: ")
    ipaddress  = input_ip.split(",")
    username = input("Username: ")
    password = getpass.getpass()
    for ip in ipaddress:
        if runFunc == 1:    
            showInterface(ip,username,password)
        if runFunc == 2:
            showVersion(ip,username,password)

if __name__ == '__main__':
    main()

运执行上面的代码，运行效果如下：　

以下代码用类也可以实现相一样的结果，可以对比一下那个方便

#!/usr/bin/env python3 
#coding=utf-8
import getpass
from netmiko import ConnectHandler
from netmiko.ssh_exception import NetMikoTimeoutException,NetMikoAuthenticationException

class NWBackup():
    def __init__(self):
        self.ip       = input('IPAddress:')
        self.username = input('Username:')
        self.password = getpass.getpass()
        self.device={'device_type': 'cisco_ios',
            'username': self.username,
            'password': self.password,
            'ip':self.ip
            }
        try:
            self.connect = ConnectHandler(**self.device)
            self.connect.enable()

        except (EOFError, NetMikoTimeoutException):
            print(u" 网络设备%s:  无法连接!请确认该设备IPAddress是否可达！" %self.ip) 
            return
         
        except (EOFError, NetMikoAuthenticationException):
            sprint(u" 网络设备%s:  用户名与密码错误!请确认账号与密码！" %self.ip)
            return

    def disVersion(self):
        cmd = 'show version'
        print(self.connect.send_command(cmd))
        self.connect.disconnect()


    def disInterface(self):
        cmd = 'show ip interface brief'
        print(self.connect.send_command(cmd))
        self.connect.disconnect()

    def runComment(self):
        disfunc = int(input('pls input num: '))
        if disfunc == 1:
            self.disVersion()
        if disfunc == 2:
            self.disInterface()

if __name__ == '__main__':
    run = NWBackup()
    run.runComment()