使用正则表达式从日志文件中提取特定文本

Question

我有以下日志文件

2020-06-30 12:44:06,608 DEBUG [main] [apitests.ApiTest] Reading of Excel File Started
2020-06-30 12:44:11,853 DEBUG [main] [apitests.ApiTest] The Keyword's Entered : Asus Laptop
2020-06-30 12:44:11,853 DEBUG [main] [apitests.ApiTest] No of Keywords Entered = 1
2020-06-30 12:44:11,853 DEBUG [main] [apitests.ApiTest] Response Code from API : 200
2020-06-30 12:44:11,853 DEBUG [main] [apitests.ApiTest] Time Taken : 1959 milliseconds
2020-06-30 12:44:11,853 DEBUG [main] [apitests.ApiTest] The Result Obtained from API is : {"keywords": {"Asus Laptop": ["Premium grade"]}}
2020-06-30 12:44:11,853 DEBUG [main] [apitests.ApiTest] --------------------------------------------------------------------------------------
2020-06-30 12:44:12,136 DEBUG [main] [apitests.ApiTest] The Keyword's Entered : Intext Hardrive
2020-06-30 12:44:12,136 DEBUG [main] [apitests.ApiTest] No of Keywords Entered = 1
2020-06-30 12:44:12,136 DEBUG [main] [apitests.ApiTest] Response Code from API : 200
2020-06-30 12:44:12,136 DEBUG [main] [apitests.ApiTest] Time Taken : 243 milliseconds
2020-06-30 12:44:12,136 DEBUG [main] [apitests.ApiTest] The Result Obtained from API is : {"keywords": {"Intext Hardrive": ["Medium grade"]}}
2020-06-30 12:44:12,136 DEBUG [main] [apitests.ApiTest] --------------------------------------------------------------------------------------

我的目标是只提取 ["premium grade"]、["Medium grade"]...等词。基本上key值的值。

我写了下面的代码。

import re
with open('quality.log', 'r') as text_file:
    text_file=text_file.read()  
    for line in text_file :  
        matches=re.findall(r"\[(.*?)\]", line)[0]
with open('qualitygrade.txt', 'w') as out:
    out.write('\n'.join(matches))

目标 re.findall(r"\[(.*?)\]", line)[0]是只提取“高级”、“中级”等

不确定我做错了什么。我的输出文本是空白的。任何帮助请。

Answer 1

此 for 将覆盖 matches 每一行

for line in text_file :  
    matches=re.findall(r"\[(.*?)\]", line)[0]

您需要 (a) 在找到匹配项时写入输出文件或 (b) 将匹配项存储在单独的变量中。 (b) 将类似于此

import re

matches = []

with open('quality.log', 'r') as text_file:
    text_file=text_file.read()  
    for line in text_file :  
        matches += re.findall(r"\[.*?\]", line)

with open('qualitygrade.txt', 'w') as out:
    out.write('\n'.join(matches))

您还需要修复您的正则表达式，因为您当前使用的正则表达式也会在您的日志中捕获一些其他标记。

Answer 2

您不需要 for 循环，因为您是一次读取整个文件。

您的代码可以是：

with open('quality.log', 'r') as text_file:
    text_file=text_file.read()
    matches = re.findall(r'\["(.*?)"]', text_file)

如果要获取双引号之间的值，应将它们添加到模式中。

\["(.*?)"]

输出

Premium grade
Medium grade

使用正则表达式从日志文件中提取特定文本

Extracting a particular text from a log file using regex

python

regex

logfile