Pipe for getting the unique values of every factor column #rstatstips

factor-values.r

get_factor_values <- . %>%
  summarise(across(
    where(is.factor),
    list(
      n = ~ length(levels(.x)),
      # could also pivot longer so that there's a row for each level...
      pos_values = ~ paste(levels(.x), collapse = "|")),
    .names = "{.col}-{.fn}"
    )) %>%
  pivot_longer(everything(), names_to = c("col_name", ".value"),
    names_sep = "-")


starwars %>%
# convert character cols to factors
  mutate(across(where(is.character), ~ factor(.x))) %>%
  get_factor_values()

#   # A tibble: 8 × 3
#   col_name       n pos_values                                                   
#   <chr>      <int> <chr>                                                        
# 1 name          87 Ackbar|Adi Gallia|Anakin Skywalker|Arvel Crynyd|Ayla Secura|…
# 2 hair_color    12 auburn|auburn, grey|auburn, white|black|blond|blonde|brown|b…
# 3 skin_color    31 blue|blue, grey|brown|brown mottle|brown, white|dark|fair|fa…
# 4 eye_color     15 black|blue|blue-gray|brown|dark|gold|green, yellow|hazel|ora…
# 5 sex            4 female|hermaphroditic|male|none                              
# 6 gender         2 feminine|masculine                                           
# 7 homeworld     48 Alderaan|Aleen Minor|Bespin|Bestine IV|Cato Neimoidia|Cerea|…
# 8 species       37 Aleena|Besalisk|Cerean|Chagrian|Clawdite|Droid|Dug|Ewok|Geon…