How can i ungroup concatenated vectors values in a data frame in R using dplyr?

Question

I have a data frame that looks like this :

var1	var2	var3
Group_A	a,b,c,d,e	1
Group_B	f,g	2
Group_C	h,i	3
Hyper_group_A	Group_A,Group_B	4
Group_D	j,k	5
Group_E	l,m	6
Group_F	n,o	7
Hyper_group_B	Hyper_group_A,p	8

i want to ungroup the elements in column var2 and to look like this :

var1	var2	var3
Group_A	a	1
Group_A	b	1
Group_A	c	1
Group_A	d	1
Group_A	e	1
Group_B	f	2
Group_B	g	2
....	...	...
....	...	...
....	...	...
Hyper_group_B	Hyper_group_A	8
Hyper_group_B	p	8

How can i do this in R using dplyr ?

var1 = c("Group_A","Group_B","Group_C","Hyper_group_A",
         "Group_D","Group_E","Group_F","Hyper_group_B")
var2 = c(c("a,b,c,d,e"),c("f,g"),c("h,i"),c("Group_A,Group_B"),
         c("j,k"),c("l,m"),c("n,o"),
         c("Hyper_group_A,p"))
var3 = seq(1,8,1)
data = tibble(var1,var2,var3);data

Answer 1

How about this:

library(dplyr)
library(tidyr)
library(stringr)
var1 = c("Group_A","Group_B","Group_C","Hyper_group_A",
         "Group_D","Group_E","Group_F","Hyper_group_B")
var2 = c(c("a,b,c,d,e"),c("f,g"),c("h,i"),c("Group_A,Group_B"),
         c("j,k"),c("l,m"),c("n,o"),
         c("Hyper_group_A,p"))
var3 = seq(1,8,1)
data = tibble(var1,var2,var3)
data %>% 
  rowwise() %>% 
  mutate(var2 = list(c(str_split(var2, ",", simplify=TRUE)))) %>% 
  unnest(var2) %>% 
  arrange(var1, var2)
#> # A tibble: 19 × 3
#>    var1          var2           var3
#>    <chr>         <chr>         <dbl>
#>  1 Group_A       a                 1
#>  2 Group_A       b                 1
#>  3 Group_A       c                 1
#>  4 Group_A       d                 1
#>  5 Group_A       e                 1
#>  6 Group_B       f                 2
#>  7 Group_B       g                 2
#>  8 Group_C       h                 3
#>  9 Group_C       i                 3
#> 10 Group_D       j                 5
#> 11 Group_D       k                 5
#> 12 Group_E       l                 6
#> 13 Group_E       m                 6
#> 14 Group_F       n                 7
#> 15 Group_F       o                 7
#> 16 Hyper_group_A Group_A           4
#> 17 Hyper_group_A Group_B           4
#> 18 Hyper_group_B Hyper_group_A     8
#> 19 Hyper_group_B p                 8

^{Created on 2022-10-19 by the reprex package (v2.0.1)}