# coding: utf-8

import paramiko
import re
from time import sleep

# 定義一個類，表示一臺遠端linux主機
class Linux(object):
  # 通過IP, 用戶名，密碼，超時時間初始化一個遠程Linux主機
  def __init__(self, ip, username, password, timeout=30):
    self.ip = ip
    self.username = username
    self.password = password
    self.timeout = timeout
    # transport和chanel
    self.t = ''
    self.chan = ''
    # 鏈接失敗的重試次數
    self.try_times = 3

  # 調用該方法連接遠程主機
  def connect(self):
    while True:
      # 連接過程中可能會拋出異常，比如網絡不通、鏈接超時
      try:
        self.t = paramiko.Transport(sock=(self.ip, 22))
        self.t.connect(username=self.username, password=self.password)
        self.chan = self.t.open_session()
        self.chan.settimeout(self.timeout)
        self.chan.get_pty()
        self.chan.invoke_shell()
        # 如果沒有拋出異常說明連接成功，直接返回
        print u'連接%s成功' % self.ip
        # 接收到的網絡數據解碼為str
        print self.chan.recv(65535).decode('utf-8')
        return
      # 這里不對可能的異常如socket.error, socket.timeout細化，直接一網打盡
      except Exception, e1:
        if self.try_times != 0:
          print u'連接%s失敗，進行重試' %self.ip
          self.try_times -= 1
        else:
          print u'重試3次失敗，結束程序'
          exit(1)

  # 斷開連接
  def close(self):
    self.chan.close()
    self.t.close()

  # 發(fā)送要執(zhí)行的命令
  def send(self, cmd):
    cmd += '\r'
    # 通過命令執(zhí)行提示符來判斷命令是否執(zhí)行完成
    p = re.compile(r':~ #')

    result = ''
    # 發(fā)送要執(zhí)行的命令
    self.chan.send(cmd)
    # 回顯很長的命令可能執(zhí)行較久，通過循環(huán)分批次取回回顯
    while True:
      sleep(0.5)
      ret = self.chan.recv(65535)
      ret = ret.decode('utf-8')
      result += ret
      if p.search(ret):
        print result
        return result

# 主機IP錯誤，無法連接的情況
if __name__ == '__main__':
  host = Linux('192.168.180.12', 'root', 'xxxx')
  host.connect()
   6   host.send('ls -l')
  host.close()
按 Ctrl+C 復制代碼按 Ctrl+C 復制代碼
連接192.168.180.12失敗，進行重試
連接192.168.180.12失敗，進行重試
連接192.168.180.12失敗，進行重試
重試3次失敗，結束程序

Process finished with exit code 1

# 鏈接正常的情況
if __name__ == '__main__':
  host = Linux('192.168.180.128', 'root', 'love')
  host.connect()
  host.send('ls -l')
  host.close()

運行結果：
連接192.168.180.128成功
Last login: Sat May 21 07:25:39 2016 from 192.168.180.1
Have a lot of fun...

ls -l
192:~ # ls -l
total 28
-rw------- 1 root root 18 May 21 07:17 .bash_history
drwxr-xr-x 1 root root 28 May 21 06:02 .config
drwx------ 1 root root 22 May 21 05:57 .dbus
drwx------ 1 root root 0 Sep 25 2014 .gnupg
drwxr-xr-x 1 root root 10 May 21 06:15 .local
-rw------- 1 root root 55 May 21 06:03 .xauth5mesuo
-rw------- 1 root root 55 May 21 07:22 .xauthEYqDmK
-rw------- 1 root root 55 May 21 07:25 .xauthGTrohO
-rw------- 1 root root 55 May 21 07:09 .xauthP90TnG
-rw------- 1 root root 48 May 21 07:40 .xauthjW8pI9
-rw------- 1 root root 48 May 21 07:40 .xauthx8T4ED
drwxr-xr-x 1 root root 0 Sep 25 2014 bin
drwxr-xr-x 1 root root 38 May 21 05:43 inst-sys
192:~ # 

Process finished with exit code 0