在两个先前已知的字符串之间处理文件的Python方式 [英] Pythonic way of processing a file between two previously known strings

问题描述

我使用python处理日志文件.假设我有一个日志文件，其中包含START行和END行，如下所示:

I process log files with python. Let´s say that I have a log file that contains a line which is START and a line that is END, like below:

START
one line
two line
...
n line
END

我想要的是能够在START和END行之间存储内容以便进行进一步处理.

What I do want is to be able to store the content between the START and END lines for further processing.

我在Python中执行以下操作:

I do the following in Python:

with open (file) as name_of_file:
    for line in name_of_file:
        if 'START' in line:  # We found the start_delimiter
            print(line)
            found_start = True
            for line in name_of_file:  # We now read until the end delimiter
                if 'END' in line:  # We exit here as we have the info
                    found_end=True
                    break
                else:

                    if not (line.isspace()): # We do not want to add to the data empty strings, so we ensure the line is not empty
                        data.append(line.replace(',','').strip().split())  # We store information in a list called data we do not want ','' or spaces
if(found_start and found_end):
    relevant_data=data

然后我处理relevant_data.

对于Python的纯净度而言，它看起来非常复杂，因此我的问题是:还有一种更Python化的方式来做到这一点吗?

Looks to far complicated for the purity of Python, and hence my question: is there a more Pythonic way of doing this?

谢谢！

推荐答案

要执行此操作，您可以使用此中讨论的iter(callable, sentinel) post ，它将一直读取直到达到前哨值为止，在您的情况下为"END"(应用.strip()之后).

To perform that, you can use iter(callable, sentinel) discussed in this post , that will read until a sentinel value is reached, in your case 'END' (after applying .strip()).

with open(filename) as file:
    start_token = next(l for l in file if l.strip()=='START') # Used to read until the start token
    result = [line.replace(',', '').split() for line in iter(lambda x=file: next(x).strip(), 'END') if line]

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