gsub() in R is not replacing '.' (dot)

Question

I want to replace dots in "2014.06.09" to "2014-06-09". I am using gsub() function for it. If

x <-  "2014.06.09"
gsub('2', '-' ,x)
# [1] "-014.06.09"

But when I try

gsub('.', '-', x)
# [1] "----------"

instead of "2014-06-09".

class(x)
# "character"

Can some suggest me a way to get this right and also why it is not working for '.' (dot)

akrun · Accepted Answer · 2015-07-20T14:50:52.777

168

You may need to escape the . which is a special character that means "any character" (from @Mr Flick's comment)

 gsub('\\.', '-', x)
 #[1] "2014-06-09"

Or

gsub('[.]', '-', x)
#[1] "2014-06-09"

Or as @Moix mentioned in the comments, we can also use fixed=TRUE instead of escaping the characters.

 gsub(".", "-", x, fixed = TRUE)

edited Jul 20 '15 at 14:50

answered Jul 20 '15 at 13:46

akrun

3

@drmariod Yes, that is an alternative – akrun Jul 20 '15 at 13:49
14

Or use `fixed = TRUE` which doesn't use regex but instead just searches for the characters. `gsub(".", "-", x, fixed = T)` – Molx Jul 20 '15 at 14:47
2

what if we want to change every single punctuation signs with something else like space? In dealing with texts from social media or reviews I come up with a lot of dots or other punctuation signs between words, because the forgot to use space after they finish the sentence. – Mehdi Abbassi Feb 24 '20 at 12:53
3

@MehdiAbbassi You can do `gsub("[[:punct:]]", " ", x)` – akrun Feb 24 '20 at 17:18

score 6 · Answer 2 · answered Mar 06 '21 at 13:06

For more complex tasks the stringr package could be interesting

library(stringr)

str_replace_all(x,"\\.","-")
## [1] "2014-06-09"

Or

str_replace_all(x,"[.]","-")
## [1] "2014-06-09"

score 4 · Answer 3 · answered Jan 25 '22 at 19:07

4

Using raw strings, introduced in R 4.0.0, one could do

gsub(r"(\.)", "-", x)
# [1] "2014-06-09"

answered Jan 25 '22 at 19:07

Maël

3 Answers3