查找 2 个或更多换行符 [英] Find 2 or more Newlines

问题描述

我的字符串看起来像:

'我看到一只小寄居蟹\r\n他的颜色太单调了\r\n\r\n很难看到蝴蝶\r\n因为他飞过天空\r\n\r\n听到鹅的鸣叫声\r\n我想他对驼鹿很生气\r\n\r\'

而且我需要在有两个或更多换行符的地方拆分它.

当然是使用 re 模块.

在这个特定的字符串 re.split(r'\r\n\r\n+', text) 上有效，但它不会捕获 \r\n\r\n\r\n，对吧?

我尝试过 re.split(r'(\r\n){2,}', text)，它在 每一行 和 处拆分re.split(r'\r\n{2,}', text)，它创建了一个 len() 1.

的列表

不应该re.split(r'(\r\n){2,}', text) == re.split(r'\r\n\r\n', text) 是 True 对于其中没有连续出现超过 2 个 \r\n?

的字符串

解决方案

re.split(r'(\r\n){2,}', text) 不会每次都拆分线.它完全符合您的要求，除了它保留了 \r\n 的一次出现，因为您已将其包含在一个捕获组中.改用非捕获组:

(?:\r\n){2,}

在这里你可以看到区别是什么:

<预><代码>>>>re.split(r'(?:\r\n){2,}', 'foo\r\n\r\nbar')['foo', 'bar']>>>re.split(r'(\r\n){2,}', 'foo\r\n\r\nbar')['foo', '\r\n', 'bar']

My string looks like:

'I saw a little hermit crab\r\nHis coloring was oh so drab\r\n\r\nIt\u2019s hard to see the butterfly\r\nBecause he flies across the sky\r\n\r\nHear the honking of the goose\r\nI think he\u2019s angry at the moose\r\n\r\'

And I need to split it wherever there are two or more newlines.

Am using the re module, of course.

On this particular string re.split(r'\r\n\r\n+', text) works, but it wouldn't catch \r\n\r\n\r\n, right?

I have tried re.split(r'(\r\n){2,}', text), which splits at every line and re.split(r'\r\n{2,}', text), which creates a list of len() 1.

Shouldn't re.split(r'(\r\n){2,}', text) == re.split(r'\r\n\r\n', text) be True for a string in which there are no consecutive occurrences of more than 2 \r\n?

解决方案

re.split(r'(\r\n){2,}', text) doesn't split at every line. It does exactly what you want, except it preserves one occurence of \r\n because you've enclosed it in a capturing group. Use a non-capturing group instead:

(?:\r\n){2,}

Here you can see what the difference is:

>>> re.split(r'(?:\r\n){2,}', 'foo\r\n\r\nbar')
['foo', 'bar']
>>> re.split(r'(\r\n){2,}', 'foo\r\n\r\nbar')
['foo', '\r\n', 'bar']

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