Transfer dataframe to list and not include NA value

Question

How to transfer dataframe to list and not include NA value ? Thanks!

There is dataframe ori_df

library(tidyverse)
ori_df <- data.frame(category=c('a','b',NA),subcategory=c('w',NA,'Z'))

Below code can transfer ori_df to list fin_list,but the result include NA

fin_list <- as.list(ori_df)

How to delete NA value in fin_list , the wished result as below fin_list_wished ?

fin_list_wished <- list(category=c('a','b'),subcategory=c('w','Z'))

Answer 1

Same idea but with purrr:

library(purrr) 
my_purrr_list <- map(as.list(my_df), discard, is.na)

my_purrr_list
#> $category
#> [1] "a" "b"
#> 
#> $subcategory
#> [1] "w" "Z"

Or without map/apply:

library(tidyverse) # tidyr, dplyr
library(magrittr)  # %$% pipe

my_dplyr_list <- my_df %>% 
  pivot_longer(everything()) %>% # columns must be the same type
  filter(!is.na(value)) %$% 
  split(value, .$name)
        
my_dplyr_list
#> $category
#> [1] "a" "b"
#> 
#> $subcategory
#> [1] "w" "Z"

Toy data:

my_df <- data.frame(category = c('a', 'b', NA), subcategory = c('w', NA, 'Z'))

^{Created on 2024-07-19 with reprex v2.1.0}