正则表达式拆分字符串：保留方括号内按键内容的实现求助

Got it, let's tackle this problem. You need to split a string such that every regular character is separated into its own element, while bracketed key identifiers (like [BKSP] or [ENTER]) are preserved as single elements. Here's a clean regex-based approach using R's stringr package:

Step-by-Step Implementation #

1. First, load the stringr package if you haven't already:

   library(stringr)
   

2. Define your input string:

   x <- "cd/etc/init[BKSP][BKSP]it.d[ENTER]"
   

3. Use str_extract_all to capture both bracketed key names and individual regular characters:

   # Match either bracketed key names (e.g., [BKSP]) or single any character
   raw_matches <- str_extract_all(x, "\\[[A-Z]+\\]|.")[[1]]
   

4. Clean up the bracketed matches to remove the square brackets:

   final_result <- sapply(raw_matches, function(item) {
     if (str_detect(item, "^\\[.*\\]$")) {
       # Remove the first and last characters (the square brackets)
       str_sub(item, 2, -2)
     } else {
       item
     }
   })
   

What the Regex Does #

• \\[[A-Z]+\\]: Matches any sequence of uppercase letters wrapped in square brackets (this targets your key names like [BKSP] or [ENTER]).
• |.: The pipe (|) acts as an OR operator, and . matches any single character (all the regular text characters you want to split individually).

Result Verification #

If you print final_result, you'll get exactly the output you're looking for:

> final_result
 [1] "c"     "d"     "/"     "e"     "t"     "c"     "/"     "i"     "n"     "i"     "t"     "BKSP"  "BKSP"  "i"     "t"     "."     "d"     "ENTER"

Alternative One-Liner #

If you prefer a more concise version, you can combine the extraction and cleanup using lookaround assertions to directly capture the text inside brackets:

final_result <- str_extract_all(x, "(?<=\\[)[A-Z]+(?=\\])|.")[[1]]

This uses positive lookbehind ((?<=\\[)) and positive lookahead ((?=\\])) to grab only the key name text without the surrounding brackets, alongside individual regular characters.

内容的提问来源于stack exchange，提问作者TuD