根据R中的模式分割字符串

Question

I have a list of strings as follows:

a <- c("aaaa 12 comments","bb cc 124 dd 134 commments","hh tt hhh 17 comments")

I would like to create two vectors, one which contains only the text and one which contains only the number of comments.

The number of comments can be different but it is always listed at the end.

Desired result:

a1 <- c("aaaa","bb cc 124 dd","hh tt hhh")
a2 <- c("12 comments","134 commments","17 comments")

Any help is much appreciated. I am trying with gsub, but it is not working:

> gsub('[:digit:]*[:space:]comments$','', a)
[1] "aaaa 12 comments"           "bb cc 124 dd 134 commments" "hh tt hhh 17 comments"  

Answer 1

Use

a1 <- gsub('([0-9]+ comments$)',"", a)
library(stringr)
a2 <- unlist(str_extract_all(a,'([0-9]+ comments$)'))