Partial Match word from sentence in R

Question

I am looking to partial match string using %in% operator in R when I run below I get FALSE

'I just want to partial match string' %in% 'partial'
 FALSE

Expected Output is TRUE in above case (because it is matched partially)

See https://stackoverflow.com/questions/10128617/test-if-characters-are-in-a-string — Wiktor Stribiżew, Sep 13 '19 at 14:31
Why do you want to use the %in% operator? this is exactly what grepl is for — MatthewR, Sep 13 '19 at 14:37
I am sorry, I am new to this. I saw %in% in few tutorials. Not sure difference between those two — , Sep 13 '19 at 14:53

score 3 · Accepted Answer · answered Sep 13 '19 at 14:30

Since you want to match partially from a sentence you should try using %like% from data.table, check below

library(data.table)
'I just want to partial match string' %like% 'partial'
 TRUE

The output is TRUE

score 1 · Answer 2 · answered Sep 13 '19 at 14:37

1

`%in_str%` <- function(pattern,s){
  grepl(pattern, s)
}

Usage:

> 'a' %in_str% 'abc'
[1] TRUE

answered Sep 13 '19 at 14:37

slava-kohut

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iod · Answer 3 · 2019-09-13T14:58:20.093

You need to strsplit the string so each word in it is its own element in a vector:

"partial" %in% unlist(strsplit('I just want to partial match string'," "))
[1] TRUE

strsplit takes a string and breaks it into a vector of shorter strings. In this case, it breaks on the space (that's the " " at the end), so that you get a vector of individual words. Unfortunately, strstring defaults to save its results as a list, which is why I wrapped it in an unlist - so we get a single vector. Then we do the %in%, which works in the opposite direction from the one you used: you're trying to find out if string partial is %in% the sentence, not the other way around.

Of course, this is an annoying way of doing it, so it's probably better to go with a grep-based solution if you want to stay within base-R, or Priyanka's data.table solution above -- both of which will also be better at stuff like matching multiple-word strings.

I do not follow this, bit advanced for my current understanding, yup will stick with above solution for now. Thank you much though — , Sep 13 '19 at 14:54
Added an explanation in my reply. Really not advanced stuff. — iod, Sep 13 '19 at 14:58

Partial Match word from sentence in R

3 Answers3