python - 逐行读取文本文件并存储匹配 Python 中特定模式的变量

Question

我们有一个很大的日志文件，包含以下两行:

00 LOG     |   Cycles Run:  120001
00 LOG     ! Virtual: Max> ?????????? bytes (?.???? gb), Current> 640733184 bytes (?.???? gb).

00 LOG     ! Virtual: Max> 1082470400 bytes (?.???? gb), Current> ????????? bytes (?.???? gb).

00 LOG     ! Actual: Max> ????????? bytes (?.???? gb), Current> 472154112 bytes (?.???? gb).

00 LOG     ! Actual: Max> 861736960 bytes (?.???? gb), Current> ????????? bytes (?.???? gb).

由于日志文件很大，我们希望逐行读取(而不是一次读取缓冲区中的整个文本)，匹配特定的模式集并在单独的变量中选择值。

例如

00 LOG     |   Cycles Run:  120001

我们希望选择 120001 并将其存储在变量 cycle 中。

另一方面，我们解析这些行:

00 LOG     ! Virtual: Max> ?????????? bytes (?.???? gb), Current> 640733184 bytes (?.???? gb).

00 LOG     ! Virtual: Max> 1082470400 bytes (?.???? gb), Current> ????????? bytes (?.???? gb).

00 LOG     ! Actual: Max> ????????? bytes (?.???? gb), Current> 472154112 bytes (?.???? gb).

00 LOG     ! Actual: Max> 861736960 bytes (?.???? gb), Current> ????????? bytes (?.???? gb).

标有?的字符可以是任何数字。

我们想要存储如下所示的变量:

640733184 in var virtual_cur

1082470400 in var virtual_max

472154112 in var actual_cur

861736960 in var actual_max

用Python 3.6编写了一个片段，但它打印了空列表:

import re

filename = "test.txt"
with open(filename) as fp:  
   line = fp.readline()
   while line:
       cycle_num = re.findall(r'00 LOG     |   Cycles Run:  (.*?)',line,re.DOTALL)
       line = fp.readline()

print (cycle_num[0])

NOTE: I want to pick each values in seperate variables and use itlater on. Need to set 5 patterns one by one, pick value if it matchesany specific pattern and put it inrespective variable.

不确定第二个模式的通配符匹配。

请建议我们一种有效地做到这一点的方法。

Answer 1

使用正则表达式

(?:(?:Cycles Run:[ \t]+)|(?:Current>[ \t]+))(\d+)

Demo

您可以按照以下方式做一些事情:

import re
pat=re.compile(r'(?:(?:Cycles Run:[ \t]+)|(?:Current>[ \t]+))(\d+)')
with open('test.txt','r') as f:   
    for line_num, line in enumerate(f):
        m=pat.search(line)
        if m:
            print(line_num, m.group(0))