python 处理telnet返回的More,以及get想要的那个参数方法

问题：

需要循环获取网元返回的某个参数，并计算出平均值。

解决方案：

通过expect解决返回More的问题。

通过具体的参数位置，精确获取到参数。

讨论：

参数位置固定，不好复用。

#! usr/bin/env python

# -*- coding: utf-8 -*-

import telnetlib
import math
import time

def get_param(b):
"获取相应的参数，返回float型参数组"
c = []
b = list(b)
length = len(b)
print length
for x in b:
c.append(float(x))
print c
return c

def get_avg(a):
"获取平均值"
length = len(a)
sum = 0
for x in a:
sum += x
avg = sum/length
return avg

def get_telnet(tn):
"获取telnet数据"
for command in commands:
tn.write('％s\n' ％ command)
time.sleep(0.5)
## result = tn.read_very_eager() # 不用read_all()，不能处理More
print "**************"
a = []
a.append('More')
print a
result = str()
while True:
 b,c,d = tn.expect(a,timeout=1)
 print b # 有More为0，无More为-1
 print 'cccccccccccccccccccccccccccccccccccccccccccc'
 print c
 print 'dddddddddddddddddddddddddddddddddddddddddddd'
 print d
 result += d
 if 0 == b:
 print "There has 'More'!!!"
 tn.write(r' ') #不用\r\n来继续
 else:
 break
print 'get result success!'
print result #获取到带More的所有返回结果
a = result.split('\r\n') # 不要加r
length = len(a)
print length
b = a[1].split(' ')
print b
print a[32]
c = a[32]
d = c.split(' ')
print d
length = len(d)
print d[8]
e = d[8].split('(')
print e[0]
return e[0]

def close_telnet(tn):
"执行完毕后，终止Telnet连接（或输入exit退出）"
tn.write('exit\n')
tn.close()

def open_telnet(Host, username, password, finish, commands):
"Telnet远程登录"
# 连接Telnet服务器
tn = telnetlib.Telnet(Host, port=23, timeout=10)
tn.set_debuglevel(2)
# 输入登录用户名
tn.read_until('Username:')
tn.write(username + '\n')
# 输入登录密码
tn.read_until('Password:')
tn.write(password + '\n')

# 登录完毕后执行命令
tn.read_until(finish)
return tn

if __name__=='__main__':
Host = '' # Telnet服务器IP
username = '' # 登录用户名
password = '' # 登录密码
finish = '#' # 命令提示符
param = []

commands = ['sho optical-module-info xgei-1/3/1']
tn = open_telnet(Host, username, password, finish, commands)
for i in range(1,10):
param.append(get_telnet(tn))
close_telnet(tn)
print param
print get_avg(get_param(param))

'''

运行结果：

37
['Optical', 'Module', 'Position', ':', 'xgei-1/3/1']
Bias-Upper : 131(mA)  Bias-Lower : 0(mA)
['Bias-Upper', '', '', '', '', '', '', ':', '131(mA)', '', '', '', '', '', '', '', '', '', '', '', '', '', '', '', 'Bias-Lower', '', '', '', '', '', '', ':', '0(mA)']
131(mA)
131
Telnet(172.10.1.123,23): send 'exit\n'
['131', '131', '131', '131', '131', '131', '131', '131', '131']
9
[131.0, 131.0, 131.0, 131.0, 131.0, 131.0, 131.0, 131.0, 131.0]
131.0
>>>
'''

来源：https://blog.csdn.net/BigDeng_2014/article/details/76921031