You've been introduced in the video to a new kind of data structure: list columns. List-columns are, as their name suggests, columns which behave like lists, but are inside a special kind of dataframe — a tibble
, which are an implementation of dataframe used in the tidyverse.
Nested dataframes — dataframes with list-columns, look like standard dataframes, but cells of that columns are not of length 1, and can contain any kind of elements. Just like a list.
df <- data.frame(
classic = c("a", "b","c"),
list = list(
c("a", "b","c"),
c("a", "b","c", "d"),
c("a", "b","c", "d", "e")
)
)
df
# A tibble: 3 x 2
classic list
<chr> <list>
1 a <chr [3]>
2 b <chr [4]>
3 c <chr [5]>
But why is this a useful format?