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如何在R[重复]中提取多个嵌套圆括号之间的字符串

string-matching string regex r

Adrian · 技术社区 · 2 年前

mystring <- c("code IS (k(384333)\n   AND parse = TURE \n ) \n 
              code IS (\n FROM (43343344)\n ) some information code IS \n
              code IS (  ( \n (data)(23423422 \n)) ) ) and more information)")

我想提取的所有实例 code IS (...) 。但是由于嵌套的括号,我的正则表达式似乎只在第一个闭括号之后停止。

library(stringr)
> str_extract_all(pattern = 'code IS \\([\\s\\S]+?\\)', mystring)
[[1]]
[1] "code IS (k(384333)"          "code IS (\n FROM (43343344)" "code IS (  ( \n (data)"

所需输出为

[[1]]
[1] "code IS (k(384333)\n   AND parse = TURE \n )"          "code IS (\n FROM (43343344)\n )" "code IS (  ( \n (data)(23423422 \n)) )"

编辑: 潜在的正则表达式解决方案包括 here :

现在的问题是如何调整这些解决方案以与 str_extract_all 在R中?

我尝试使用PCRE模式:

> str_extract_all(pattern = 'code IS \((?:[^)(]+|(?R))*+\)', mystring)
Error: '\(' is an unrecognized escape in character string starting "'code IS \("