CODEWITHSUNDEEP
rregex
SA2018
SA2018

Reputation: 367

How extract from a string after specific word

I have this string :

string <-"DIS_S_CD_EFS-NO_PCI-CD_ACT_CG-SOM_MT_ECT_CVE"

I need to extract only SOM_MT_ECT_CVE from it.

So for me the key word is SOM (identify its position ).

I tried using this :

d <-substr(gregexpr(pattern ='SOM',"DIS_S_CD_EFS-NO_PCI-CD_ACT_CG-SOM_MT_ECT_CVE"),
           nchar("DIS_S_CD_EFS-NO_PCI-CD_ACT_CG-SOM_MT_ECT_CVE"),"DIS_S_CD_EFS-NO_PCI-CD_ACT_CG-SOM_MT_ECT_CVE")

But it return NA values.

Upvotes: 2

Views: 5402

Answers (2)

akrun
akrun

Reputation: 887118

One option is sub to match characters (.*) until 'SOM', capture the 'SOM' to the rest of the characters in a group ((...)) and in the replacement use the backreference (\\1) of the captured group

sub(".*(SOM_.*)", "\\1", string)
#[1] "SOM_MT_ECT_CVE"

Or using stringr

library(stringr)
str_extract(string, "SOM.*")
#[1] "SOM_MT_ECT_CVE"

Upvotes: 2

Sotos
Sotos

Reputation: 51592

You can split on the hyphen and get the last word, i.e.

tail(strsplit(string, '-', fixed = TRUE)[[1]], 1)
#[1] "SOM_MT_ECT_CVE"

Or with word from stringr,

stringr::word(string, -1, sep = '-')
#[1] "SOM_MT_ECT_CVE"

Upvotes: 1

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