python - 我的 Python 正则表达式代码没有给出我预期的输出

Question

我试图从文本文件中提取并解析单词(主机名和版本)。当我运行代码时，它将数据写入 csv 文件，但输出看起来不同。

 **my input file is .txt and below is the content** 
 Hostname Router1
 version 15.01
 code:
 line console 0
 logging synchronous
 exec-timeout 15 1
 usb-inactivity-timeout 15
 exec prompt timestamp
 transport preferred none

Hostname Router2
version 15.02
line vty 0 15
logging synchronous
exec-timeout 15 2
exec prompt timestamp
transport input ssh
transport preferred none
access-class REMOTE_ACCESS in

Hostname Router3
version 15
line console 0
logging synchronous
exec-timeout 15 3
usb-inactivity-timeout 15
exec prompt timestamp
transport preferred none

Hostname Router3
version 15.12
line vty 0 15
logging synchronous
exec-timeout 15 4
exec prompt timestamp
transport input ssh
transport preferred none
access-class REMOTE_ACCESS in
**Above is the sample content in my input text file**
$
import re
import csv
with open('sample5.csv','w',newline='') as output:
    HeaderFields = ['Hostname','version']
    writer = csv.DictWriter(output,fieldnames=HeaderFields)
    writer.writeheader()
with open('testfile.txt','r',encoding='utf-8') as input:
    for line in input.readlines():
       pattern = re.compile(r'Hostname(.*)''|''version(.*)')
       match=pattern.finditer(line)
       for match1 in match:
          with open('sample5.csv', 'a',newline='') as output:
              writer = csv.DictWriter(output, fieldnames=HeaderFields)
              writer.writerow({'Hostname': match1.group(1), 'version':  
                                match1.group(2)})

我的 csv 预期结果如下:

谢谢。

Answer 1

您的代码失败，因为在每次迭代中您只读取一行(可以包含主机或版本，但不能同时包含两者，但您将数据写入 csv。让我们在匹配双线时迭代所有文本:第一行主机名.. 第二行版本...\n 作为 Windows 的换行符(我听说 Mac 使用\r 不确定)。现在，由于您匹配了双线，您可以从同一匹配对象中获取路由器和版本。

with open('testfile.txt','r',encoding='utf-8') as input:
       txt = input.read()
       pattern = re.compile(r'Hostname (.*)(\r\n?|\n)version (.*)')
       match=pattern.finditer(txt)
       for match1 in match:
          with open('sample5.csv', 'a',newline='') as output:
             writer = csv.DictWriter(output, fieldnames=HeaderFields)
             writer.writerow({'Hostname': match1.group(1), 'version':  
                            match1.group(3)})