Remove (or replace) everything after a specified character in R strings

Question

I have a column of strings that I would like to remove everything after the last '.'

I tried:

sub('\\..*', '', x)

But my problem is is that for some of the stings there are x2 '.' and for some only x1 '.' eg

ENST00000338167.9
ABCDE.42927.6

How can I remove only characters after the last '.'?? So that I'm left with:

ENST00000338167
ABCDE.42927

Many thanks!!

Answer 1

We can use sub to match the . (escaped as it is a metacharacter for any character) followed by 0 or more characters that are not a . ([^.]*) until the end ($) of the string and replace it with blank ("")

sub("\\.[^.]*$", "", x)
#[1] "ENST00000338167" "ABCDE.42927"    

---

Or use str_remove from stringr

library(stringr)
str_remove(x, "\\.[^.]*$")
#[1] "ENST00000338167" "ABCDE.42927"  

data

x <- c("ENST00000338167.9", "ABCDE.42927")  

Answer 2

Yet another way is by "capturing" the part before.

sub("(.*)\\..*", "\\1", x)