remove close parenthesis in a string when parenthesis is not opened in r

user_4806121 0
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I wanted to remove closing parentheses, ")", in a string when there is no opening parenthesis ahead. Here are examples and my desired output.

string1= "1548-(2), 1549)"
string2= "1401-(15~145), 153), 156"

desired_string1= "1548-(2), 1549"
desired_string2= "1401-(15~145), 153, 156"

*Additional: Thank you for the answers, it works well but it doesn't for the following case:

additional = "1543-(2, 6), 1548-(2), 1549), 1334-(1~5),  1401-(15, 145)"
desired_additional = "1543-(2, 6), 1548-(2), 1549, 1334-(1~5),  1401-(15, 145)"
stringr r
3 Answers

We could create a function to get the location of the parentheses and if there is any unbalanced one, then the length of one of them would be different, use that location in substr or str_sub to change it to ""

library(stringr)
f1 <- function(str1) {
   i1 <- str_locate_all(str1, '\\(')[[1]][,1]
   i2 <- str_locate_all(str1, '\\)')[[1]][,1]
   i3 <- seq_along(i2) > length(i1)
   if(any(i3)) {
      i4 <- i2[i3 ]
      str_sub(str1, i4, i4) <- ''
   }
   return(str1)
  }

-testing

f1(string1)
#[1] "1548-(2), 1549"
f1(string2)
#[1] "1401-(15~145), 153, 156"

f1("((a))")
#[1] "((a))"

f1("(a))")
#[1] "(a)"

Using the updated 'additional'

paste(sapply(strsplit(additional, "(?<=\\)),", perl = TRUE)[[1]], 
       f1), collapse=",")
#[1] "1543-(2, 6), 1548-(2), 1549, 1334-(1~5),  1401-(15, 145)"
user_37322710

Here is another solution using stringr package

fun <- function(x) {
  library(stringr)
  open_cnt = str_count(x, "\\(")                      # counts opening parentheses
  close_cnt = str_count(x, "\\)")                     # counts closing parentheses
  if(close_cnt > open_cnt){ 
    diff_i = (open_cnt+1):close_cnt                         # indexes differences
    diff_loc = str_locate_all(x, "\\)")[[1]][diff_i,1]      # locates differences
    paste0(unlist(str_split(x,""))[-diff_loc], collapse="") # rebuilds string
  } else {x}
}

fun(string1)
#[1] "1548-(2), 1549"
fun(string2)
#[1] "1401-(15~145), 153, 156"
fun("((( 0__0 ))))))))))")
#[1] "((( 0__0 )))"
user_62880650

You can use lookbehind and lookahead:

library(stringr)
str_replace_all(str, "(?<=,[^)]{1,10})\\)(?=,|$)", "")
[1] "1548-(2), 1549"          "1401-(15~145), 153, 156"

Here we remove only those )s that (i) follow a , followed by 1-10 characters which are not ) and that (ii) precede either a ,or the end of the string.

Data:

str = c("1548-(2), 1549)", "1401-(15~145), 153), 156")

EDIT:

If the data is more complicated, like this:

str = c("1548-(2), 1549))", "1401-(15~145), 153) ),) 156)")

you can use negative lookbehind:

str_replace_all(str, "(?<!\\([^)]{0,10})\\)\\)?", "")
[1] "1548-(2), 1549"          "1401-(15~145), 153, 156"

Here we remove one or two consecutive )s if there is no opening round parenthesis ( to the left at any distance between 0 and 10 characters (which must not include any )).

user_80399780
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