如何移除R语言字符串中的内层嵌套括号？

可以使用stringr包的str_replace_all()结合正则表达式，精准匹配并删除内层括号：

library(stringr)

test <- c(
  "Record ID", 
  "What is the best food? (choice=Nachos)", 
  "What is the best food? (choice=Tacos (big bent nachos))", 
  "What is the best food? (choice=Chips with stuff)", 
  "Complete?"
)

# 删除内层括号
result <- str_replace_all(test, "(?<=[(][^()]*)\\(|\\)(?=[^()]*[)])", "")

print(result)

输出结果 #

[1] "Record ID"                                          
[2] "What is the best food? (choice=Nachos)"             
[3] "What is the best food? (choice=Tacos big bent nachos)"
[4] "What is the best food? (choice=Chips with stuff)"   
[5] "Complete?"

正则表达式说明 #

• (?<=[(][^()]*)\\(：匹配外层括号内部的左括号，通过正向断言确保该左括号前是外层左括号，且中间无其他括号干扰
• \\)(?=[^()]*[)])：匹配外层括号内部的右括号，通过正向断言确保该右括号后是外层右括号，且中间无其他括号干扰
• 用|连接两种匹配规则，一次性替换所有内层的(和)

多层嵌套场景处理 #

如果存在多层嵌套（比如(a(b(c)))），可以循环执行替换直到没有内层括号残留：

# 处理多层嵌套的情况
result_multi <- test
while(str_detect(result_multi, "(?<=[(][^()]*)\\(|\\)(?=[^()]*[)])")) {
  result_multi <- str_replace_all(result_multi, "(?<=[(][^()]*)\\(|\\)(?=[^()]*[)])", "")
}

print(result_multi)

内容的提问来源于stack exchange，提问作者itsMeInMiami