How to add a missing closing parenthesis to a string in R?

user_19533566 0
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I would like to add a closing parenthesis to strings that have an open parenthesis but are missing a closing parenthesis. For instance, I would like to modify "The dog walked (ABC in the park" to be "The dog walked (ABC) in the park".

I found a similar question and solution but it is in Python (How to add a missing closing parenthesis to a string in Python?). I have tried to modify the code to be used in R but to no avail. Can someone help me with this please?

I have tried modifying the original python solution as R doesn't recognise the "r" and "\" has been replaced by "\\" but this solution doesn't work properly and does not capture the string preceded before the bracket I would like to add:

text = "The dog walked (ABC in the park"
str_replace_all(text, '\\([A-Z]+(?!\\))\\b', '\\)') 
text

The python solution that works is as follows:

text = "The dog walked (ABC in the park"
text = re.sub(r'(\([A-Z]+(?!\))\b)', r"\1)", text)
print(text)
r regex string
3 Answers

Try this

stringr::str_replace_all(text, '\\([A-Z]+(?!\\))\\b', '\\0\\)')
  • output
"The dog walked (ABC) in the park"
user_191983370

You might also use gsub, and first use the word boundary and then the negative lookahead.

In the replacement use the first capture group followed by )

text = "The dog walked (ABC in the park"
gsub('(\\([A-Z]+)\\b(?!\\))', '\\1\\)', text, perl=T)

Output

[1] "The dog walked (ABC) in the park"
user_54249880

Not a one liner, but it does the trick and is (hopefully!) intuitive.

library(stringr)

add_brackets = function(text) {
    brackets = str_extract(text, "\\([:alpha:]+") # finds the open bracket and any following letters
    brackets_new = paste0(brackets, ")") # adds in the closing brackets
    str_replace(text, paste0("\\", brackets), brackets_new) # replaces the unclosed string with the closed one
}

> add_brackets(text)
[1] "The dog walked (ABC) in the park"
user_57847570
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