聊天消息的正则表达式答案

【问题标题】：Regex for chat messages聊天消息的正则表达式
【发布时间】：2020-08-11 04:07:09
【问题描述】：

我有一个聊天对话日志，我希望每个组的类型为 (Stranger|You): message。以下是聊天记录的格式：

foofoofoofoofoofooStranger: heyy You: asdasdasdassdasad Stranger: asdasdasd You: Stranger:asdasdasd You: bye You have disconnected.\n\n \n\n \n\x0c

我试过(Stranger:\s|You:\s)(.*?)(Stranger:\s|You:\s)，但效果不太好。

【问题讨论】：

您可以将最后一部分更改为正向前瞻 (Stranger:\s|You:\s)(.*?)(?=Stranger:\s|You:\s) regex101.com/r/bnDFVT/1 或直到字符串末尾 (Stranger:\s|You:\s)(.*?)(?=Stranger:\s|You:\s|$) regex101.com/r/cpD6kS/1

标签： regex chat

【解决方案1】：

您可以将最后一个捕获组更改为正向前瞻(?=。

为了也匹配最后一部分，您可以添加$ 来断言字符串的结尾。

(Stranger:\s|You:\s)(.*?)(?=Stranger:\s|You:\s|$)

Regex demo

【讨论】：

【解决方案2】：

使用

((?:Stranger|You):\s+)((?:(?!(?:Stranger|You):\s).)*)

见proof

解释

NODE                     EXPLANATION
--------------------------------------------------------------------------------
  (                        group and capture to \1:
--------------------------------------------------------------------------------
    (?:                      group, but do not capture:
--------------------------------------------------------------------------------
      Stranger                 'Stranger'
--------------------------------------------------------------------------------
     |                        OR
--------------------------------------------------------------------------------
      You                      'You'
--------------------------------------------------------------------------------
    )                        end of grouping
--------------------------------------------------------------------------------
    :                        ':'
--------------------------------------------------------------------------------
    \s+                      whitespace (\n, \r, \t, \f, and " ") (1
                             or more times (matching the most amount
                             possible))
--------------------------------------------------------------------------------
  )                        end of \1
--------------------------------------------------------------------------------
  (                        group and capture to \2:
--------------------------------------------------------------------------------
    (?:                      group, but do not capture (0 or more
                             times (matching the most amount
                             possible)):
--------------------------------------------------------------------------------
      (?!                      look ahead to see if there is not:
--------------------------------------------------------------------------------
        (?:                      group, but do not capture:
--------------------------------------------------------------------------------
          Stranger                 'Stranger'
--------------------------------------------------------------------------------
         |                        OR
--------------------------------------------------------------------------------
          You                      'You'
--------------------------------------------------------------------------------
        )                        end of grouping
--------------------------------------------------------------------------------
        :                        ':'
--------------------------------------------------------------------------------
        \s                       whitespace (\n, \r, \t, \f, and " ")
--------------------------------------------------------------------------------
      )                        end of look-ahead
--------------------------------------------------------------------------------
      .                        any character except \n
--------------------------------------------------------------------------------
    )*                       end of grouping
--------------------------------------------------------------------------------
  )                        end of \2

【讨论】：