How to name a list of a group_split in dplyr when grouped by more than one column

Question

I am using group_split in dplyr and I am struggling to name the list after I have split by more than one column.

I know how to do this when we group by one column here but I am not sure how to do this when splitting by two columns

I can't share the data but if using the iris dataset, it would be similar to this (in my case both columns are factors)

iris %>%
group_split(Species, Petal.Width)

Answer 1

Use dplyr::group_keys() to get the grouping variables.

library(dplyr)
library(stringr)
# make grouped data frame
iris_group <- iris %>%
    group_by(Species, Petal.Width)

# get group keys
group_name_df <- group_keys(iris_group) %>%
    mutate(group_name = str_c(as.character(Species),"-",Petal.Width))

# get name for each group
group_name <- group_name_df$group_name

# assign name to each split table
df_list <- group_split(iris_group) %>%
    setNames(group_name)

> group_name_df
# A tibble: 27 x 3
   Species    Petal.Width group_name    
   <fct>            <dbl> <chr>         
 1 setosa             0.1 setosa-0.1    
 2 setosa             0.2 setosa-0.2    
 3 setosa             0.3 setosa-0.3    
 4 setosa             0.4 setosa-0.4    
 5 setosa             0.5 setosa-0.5    
 6 setosa             0.6 setosa-0.6    
 7 versicolor         1   versicolor-1  
 8 versicolor         1.1 versicolor-1.1
 9 versicolor         1.2 versicolor-1.2
10 versicolor         1.3 versicolor-1.3
# ... with 17 more rows

> df_list 
$`setosa-0.1`
# A tibble: 5 x 5
  Sepal.Length Sepal.Width Petal.Length Petal.Width Species
         <dbl>       <dbl>        <dbl>       <dbl> <fct>  
1          4.9         3.1          1.5         0.1 setosa 
2          4.8         3            1.4         0.1 setosa 
3          4.3         3            1.1         0.1 setosa 
4          5.2         4.1          1.5         0.1 setosa 
5          4.9         3.6          1.4         0.1 setosa 

$`setosa-0.2`
# A tibble: 29 x 5
   Sepal.Length Sepal.Width Petal.Length Petal.Width Species
          <dbl>       <dbl>        <dbl>       <dbl> <fct>  
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