网络工程师的Python之路——TextFSM

• 参考阅读
• 重点核心（正则内容）
• tracert信息的TextFSM整形
• version信息的整形

网络工程师的Python之路–汇总
关于TextFSM的详细解读，点击如下URLTextFSM：强无敌的配置解析利器-全面解读

正则如何匹配，不做过多赘述，再后续的数据整形中品味正则是如何使用的

模板文件位置：位于同级目录下template目录下的stracert.template

Value ID (d+)
Value Hop (S+)

Start
 ^ ${ID} ${Hop} +d+ -> Record

标准格式写法注意事项：

• 变量声明后空一行；每一个变量就是一个rule
• Start顶头写且换行后至少空一格；^后面就是之前定义的rule
• 最后一个 -> Record代表识别到后把之前识别的都写入一条记录；箭头的左右侧必须有空格

def tracer(str1):
    info = TextFSM(open('templatestracert.template')).ParseText(str1)  # 
    print(TextFSM(open('templatestracert.template')).header)
    return  info


str1 = '''
tracert 192.5.5.5
tracert 192.5.5.5
 traceroute to  192.5.5.5(192.5.5.5), max hops: 30 ,packet length: 40,press CTRL_C to break 
 1 36.1.1.6 60 ms  50 ms  10 ms 
 2 67.1.1.7 100 ms  90 ms  80 ms 
 3 78.1.1.8 90 ms  80 ms  60 ms 
 4 59.1.1.9 100 ms  90 ms  80 ms 
 5 59.1.1.5 90 ms  100 ms  60 ms
'''

if __name__ == "__main__":
    key = tracer(str1)
    print(key)

执行：

['ID', 'Hop']
[['1', '36.1.1.6'], ['2', '67.1.1.7'], ['3', '78.1.1.8'], ['4', '59.1.1.9'], ['5', '59.1.1.5']]

可以看到，这样就将半结构化的string整形成了list，至此就可以随意提取任何想要的信息，比如此时我想要看第4跳到哪了？

if __name__ == "__main__":
    key = tracer(str1)
    print(key)
    print(type(key))
    print(key[3])
 
 ['ID', 'Hop']
[['1', '36.1.1.6'], ['2', '67.1.1.7'], ['3', '78.1.1.8'], ['4', '59.1.1.9'], ['5', '59.1.1.5']]

['4', '59.1.1.9']

若想要提取第4跳的IP就继续增加[]

if __name__ == "__main__":
    key = tracer(str1)
    print(key)
    print(type(key))
    print(key[3])
    print(key[3][1])

['ID', 'Hop']
[['1', '36.1.1.6'], ['2', '67.1.1.7'], ['3', '78.1.1.8'], ['4', '59.1.1.9'], ['5', '59.1.1.5']]

['4', '59.1.1.9']
59.1.1.9

模板内容

Value version (d+.d+(d+)w+d+)
Value linux (S+)
Value time (d+s+hours, d+s+minutes)
Value image (S+)

Start
 ^s+Version: Versions+${version}
 ^s+Linux Softwares+${linux}
 ^s+Router uptime iss+${time}
 ^s+System image file iss+${image} -> Record

def version(str):
    info = TextFSM(open('templatesversion.template')).ParseTextToDicts(str)  # 
    print(TextFSM(open('templatesversion.template')).header)
    return  info
str2 = '''
Router#sho version
    Cisco IOS Software
    Linux Software (I86BI_LINUX-ADVENTERPRISEK9-M)
    Version: Version 15.4(2)T4
    DEVELOPMENT TEST SOFTWARE 
    Technical Support: http://www.cisco.com/techsupport
    Copyright (c) 1986-2015 by Cisco Systems, Inc.
    Compiled Thu 08-Oct-15 21:21 by prod_rel_team
    
    ROM: Bootstrap program is Linux
    
    Router uptime is 14 hours, 41 minutes
    System returned to ROM by reload at 0
    System image file is "unix:/opt/unetlab/addons/iol/bin/L3_ADVENTERPRISEK9_M_15.4_2T.bin"
    Last reload reason: Unknown reason
'''


if __name__ == "__main__":
    key = version(str2)
    print(key)
    print(type(key))
执行结果：
['version', 'linux', 'time', 'image']
[{'version': '15.4(2)T4', 'linux': '(I86BI_LINUX-ADVENTERPRISEK9-M)', 'time': '14 hours, 41 minutes', 'image': '"unix:/opt/unetlab/addons/iol/bin/L3_ADVENTERPRISEK9_M_15.4_2T.bin"'}]