How to remove punctuation excluding negations?

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Let's assume I have the following sentence:


s = c("I don't want to remove punctuation for negations. Instead, I want to remove only general punctuation. For example, keep I wouldn't like it but remove Inter's fan or Man city's fan.")

I would like to have the following outcome:

"I don't want to remove punctuation for negations Instead I want to remove only general punctuation For example keep I wouldn't like it but remove Inter fan or Man city fan."

At the moment if I simply use the code below, I remove both 's and ' in the negations.


  s %>%  str_replace_all("['']s\\b|[^[:alnum:][:blank:]@_]"," ")

 "I don t want to remove punctuation for negations  Instead  I want to remove only general punctuation           For example  keep I wouldn t like it but remove Inter  fan or Man city  fan "

To sum up, I need to have a code that removes general punctuation, including "'s" except for negations that I want to keep in their raw format.

Can anyone help me ?

Thanks!

stringr punctuation r regex
2 Answers

You can use a look ahead (?!t) testing that the [:punct:] is not followed by a t.

gsub("[[:punct:]](?!t)\\w?", "", s, perl=TRUE)
#[1] "I don't want to remove punctuation for negations Instead I want to remove only general punctuation For example keep I wouldn't like it but remove Inter fan or Man city fan"

In case you want to be more strict you can test in addition if there is no n before with (?<!n).

gsub("(?<!n)[[:punct:]](?!t)\\w?", "", s, perl=TRUE)

Or in case to restrict it only to 't (thanks to @chris-ruehlemann)

gsub("(?!'t)[[:punct:]]\\w?", "", s, perl=TRUE)

Or remove every punct but not ' or 's:

gsub("[^'[:^punct:]]|'s", "", s, perl = TRUE)

The same but use look ahead:

gsub("(?!')[[:punct:]]|'s", "", s, perl = TRUE)
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