CODEWITHSUNDEEP
r
road
road

Reputation: 479

unlist strings and paste/concatenate in R

I have a huge dataframe with a list column(e.g): 

join_name <- structure(list(text = list(c("The", "lady", "you", "love"), 
    c("The", "dog", "you", "love"))), row.names = c(NA, -2L), 
    class = "data.frame")

I would like to paste them together like:

join_name$text=
    [1] "The lady you love"
    [2] "The dog you love"

This loop do the job but is waaaay too slow :

for(i in 1:length(join_name$text)){
  join_name$text[i]=paste(unlist(join_name$text[i], use.names=FALSE),collapse=" ")
}

Any idea how to do this? Thank you!

Upvotes: 1

Views: 2053

Answers (2)

camille
camille

Reputation: 16842

Here's a tidyverse way that, for a simple case, isn't really any better than base sapply, but for more complicated workflow might have its benefits and therefore I figured it was worth adding. It replaces sapply with purrr::map_chr and paste with stringr::str_c.

library(purrr)
library(stringr)

join_name <- structure(list(text = list(c("The", "lady", "you", "love"), 
                                        c("The", "dog", "you", "love"))), row.names = c(NA, -2L), 
                       class = "data.frame")

map_chr(join_name$text, str_c, collapse = " ")
#> [1] "The lady you love" "The dog you love"

Upvotes: 1

road
road

Reputation: 479

Thanks @MrFlick. Answer is:

join_name$text <- sapply(join_name$text, paste, collapse=" ")

Upvotes: 3

Related Questions