Getting the unique count of strings from a text string

Question

I am wondering on how to get the unique number of characters from the text string. Let's say I am looking for a count of repetition of the words apples, bananas, pineapples, grapes in this string.

 A<- c('I have a lot of pineapples, apples and grapes. One day the pineapples person gave the apples person two baskets of grapes')

 df<- data.frame(A) 

Let's say I want to get all the unique count of the fruits listed in the text.

  library(stringr)
  df$fruituniquecount<- str_count(df$A, "apples|pineapples|grapes|bananas")

I tried this but I get the over all count. I would like to the answer as '3'. Please suggest your ideas.

Answer 1

You could use str_extract_all and then calculate the length of the unique elements.

Input:

A <- c('I have a lot of pineapples, apples and grapes. One day the pineapples person gave the apples person two baskets of grapes')
fruits <- "apples|pineapples|grapes|bananas"

Result

length(unique(c(stringr::str_extract_all(A, fruits, simplify = TRUE))))
# [1] 3

Answer 2

Not exactly elegant, but you could use str_detect like this.

sum(str_detect(df$A, "apples"), 
    str_detect(df$A, "pineapples"), 
    str_detect(df$A, "grapes"), 
    str_detect(df$A, "bananas"))

Or, based on the comments below, if you put all these terms in their own vector you could then use an apply function:

fruits <- c("apples", "pineapples", "grapes", "bananas")
sum(sapply(fruits, function(x) str_detect(df$A, x)))