提取两个标记之间的所有子字符串 [英] Extract all substrings between two markers

问题描述

我有一个字符串:

mystr = "&marker1\nThe String that I want /\n&marker1\nAnother string that I want /\n"

我想要的是标记start="&maker1"和end="/\n"之间的子字符串列表.因此，预期结果是:

What I want is a list of substrings between the markers start="&maker1" and end="/\n". Thus, the expected result is:

whatIwant = ["The String that I want", "Another string that I want"]

我在这里阅读了答案:

1. 在两个子字符串之间查找字符串[重复]
2. 如何提取两个标记之间的子字符串?

1. Find string between two substrings [duplicate]
2. How to extract the substring between two markers?

并尝试了此尝试，但未成功

And tried this but not successfully,

>>> import re
>>> mystr = "&marker1\nThe String that I want /\n&marker1\nAnother string that I want /\n"
>>> whatIwant = re.search("&marker1(.*)/\n", mystr)
>>> whatIwant.group(1)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'NoneType' object has no attribute 'group'

我该怎么做才能解决此问题?而且，我的字符串很长

What could I do to resolve this? Also, I have a very long string

>>> len(myactualstring)
7792818

推荐答案

该如何解决? 我会的:

import re
mystr = "&marker1\nThe String that I want /\n&marker1\nAnother string that I want /\n"
found = re.findall(r"\&marker1\n(.*?)/\n", mystr)
print(found)

输出:

['The String that I want ', 'Another string that I want ']

请注意:

如果需要文字&，
• &在re模式中具有特殊含义.您需要对其进行转义(\&)
• .匹配除换行符之外的所有内容
如果只想要匹配的子字符串列表而不是search ，则
• findall更适合选择
• *?是非贪婪的，在这种情况下.*也可以工作，因为.与换行符不匹配，但是在其他情况下，匹配结束可能会超出您的期望
• 我使用了所谓的raw-string(r前缀)使转义变得更容易

• & has special meaning in re patterns, if you want literal & you need to escape it (\&)
• . does match anything except newlines
• findall is better suited choiced if you just want list of matched substrings, rather than search
• *? is non-greedy, in this case .* would work too, because . do not match newline, but in other cases you might ending matching more than you wish
• I used so-called raw-string (r-prefixed) to make escaping easier

阅读模块re 文档讨论原始字符串的用法以及具有特殊含义的隐式字符列表.

Read module re documentation for discussion of raw-string usage and implicit list of characters with special meaning.

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