Replace NULLs in a list-column with NAs

This function takes a list and replaces all NULL values with NA. It is useful for working with list-columns in a data frame. Parallelization is supported via purrr::in_parallel().

Usage

gen_na_listcol(.x)

Arguments

.x

A list or list-column to modify.

Value

A list with all NULL values replaced with NA.

Examples

library(dplyr)
#> 
#> Attaching package: ‘dplyr’
#> The following objects are masked from ‘package:stats’:
#> 
#>     filter, lag
#> The following objects are masked from ‘package:base’:
#> 
#>     intersect, setdiff, setequal, union

a <-
  mtcars %>%
  select(cyl, vs, am) %>%
  slice(1:6) %>%
  as_tibble() %>%
  mutate(listcol = list(NULL, "b", "c", "d", "e", "f"))
glimpse(a)
#> Rows: 6
#> Columns: 4
#> $ cyl     <dbl> 6, 6, 4, 6, 8, 6
#> $ vs      <dbl> 0, 0, 1, 1, 0, 1
#> $ am      <dbl> 1, 1, 1, 0, 0, 0
#> $ listcol <list> <NULL>, "b", "c", "d", "e", "f"

b <-
  a %>%
  mutate(across(starts_with("listcol"), gen_na_listcol))
glimpse(b)
#> Rows: 6
#> Columns: 4
#> $ cyl     <dbl> 6, 6, 4, 6, 8, 6
#> $ vs      <dbl> 0, 0, 1, 1, 0, 1
#> $ am      <dbl> 1, 1, 1, 0, 0, 0
#> $ listcol <list> NA, "b", "c", "d", "e", "f"