Remove duplicates within a string across one colum of a dataframe in R

Question

col1	col2
First,First,Second	row,First,First
Second,Second,Third	row,Second,Second

I would like to transform col1 into to this, without removing duplicates in col2 and without creating new rows

col1	col2
First,Second	row,First,First
Second,Third	row,Second,Second

And what if the separator is a || instead of a ,?

@Mael possibly not a dupe, since the OP asked to remove duplicates, not just remove everything after the first comma. — user438383, Jan 19 '22 at 10:01
@Karlos could you clarify whether you just want to remove everything after the first comma, or remove all duplicated values? — user438383, Jan 19 '22 at 10:12
The separator is not a comma but a || I want to revome duplicates in col1, only — Karlos Garcia, Jan 19 '22 at 10:16
the example you provided is a single vector. i have multiple vectors inside the variable of a data frame — Karlos Garcia, Jan 19 '22 at 11:28
I added 2 links, one for vector one for dataframe, but the solution idea is the same: `"split, unlist, uniq, paste"` — zx8754, Jan 19 '22 at 11:30

score 0 · Answer 1 · answered Jan 19 '22 at 09:59

0

One option using tidyr and dplyr

dat %>% separate_rows(col1) %>% distinct(col1, col2)

# A tibble: 2 × 2
  col1   col2             
  <chr>  <chr>            
1 First  row,First,First  
2 Second row,Second,Second

answered Jan 19 '22 at 09:59

user438383

I do not want to create new rows. Mantain existing ones. What if we have in Col1 something like c(First,First,Second) and c(Second,Second,Third). The data frame will increase in number of rows – Karlos Garcia Jan 19 '22 at 10:53
@Karlos can you update the data in your question and I will update my answer. – user438383 Jan 19 '22 at 11:07
updated, thank you – Karlos Garcia Jan 19 '22 at 11:12

score -1 · Answer 2 · answered Jan 19 '22 at 09:59

-1

You could split the first column on comma, to generate a vector. Then, use unique() and finally recreate the CSV:

df$col1 <- paste(unique(strsplit(df$col1, ",")[[1]]), collapse=",")

answered Jan 19 '22 at 09:59

Tim Biegeleisen

2 Answers2