How to put double quotes in other double quotes

Question

library(tidyverse)

Here is the representation of my dataset:

mydata<-data.frame(NCT_number=c(" 1111","  2222","0000","3333","4444 ")

I want to spots characters that are preceded or followed by blanks: One space, two spaces and so on. I tried this:

mydata%>%filter(str_detect(NCT_number,c(" " "|"  " ")))

My expected result is:

  NCT_number
1       1111
2       2222
5      4444

But it didn't works.

Could you please make the question reproducible, provide some sample data: paste the output of `dput(head(mydata$NCT_number, 10))` into the question, as a minimum and included your expected outcome. — Peter, Nov 30 '21 at 15:51
Can you please update the title as in its present form it is far from reflecting the actual content of your question — Chris Ruehlemann, Nov 30 '21 at 16:19

score 1 · Answer 1 · answered Nov 30 '21 at 16:09

library(dplyr)
mydata %>%
  filter(grepl("^\\s|\\s$", NCT_number))
  NCT_number
1       1111
2       2222
3      4444

Here we are making use of the 'anchors' ^, which denotes the start position of the string, and $, which denotes the end position of the string.

With base R:

mydata[grepl("^\\s|\\s$", mydata$NCT_number),]
[1] " 1111"  "  2222" "4444 "

1 Answers1