python 解析文本文件中的条件多行

Question

我想解析一个文本文件，但有多个条件:

输入:

something<br />
something <br />
something<br />
Modifications made by xy (xy) on 2019/12/10 10:40:23<br />
location: A --> B<br />
something<br />
something<br />
something<br />
Modifications made by xz (xz) on 2020/01/17 11:11:59<br />
analyzer: C --> D<br />
analyzer: B --> D<br />
analyzer: G --> D<br />
location: E --> F<br />
something<br />
something<br />
something

任务:我需要找到“位置:x --> y”和位置之前的日期。 txt 文件可能包含未知数量的位置更改。

所需输出:

2019/12/10 10:40:23, location: A --> B
2020/01/17 11:11:59, location: E --> F

我尝试了一些代码，例如:

with open('log.txt', 'r') as searchfile:
    for line in searchfile:
        if 'location' in line:
            print (line)

但只找到地点，不知道如何找到它们的日期。

提前谢谢您。

Answer 1

只需跟踪相应的时间和地点即可:

with open('log.txt', 'r') as searchfile:
    time = None
    for line in searchfile:
        if line.startswith('Modifications made by'):
            time = line.split('on')[-1].strip()
        elif line.startswith('location') and time is not None:
            print(f'{time}, {line}')