Get the last n
values of a list
Description
Get the last n
values of a list
Usage
<Expr>$list$tail(n = 5L)
Arguments
n
|
Number of values to return for each sublist. Can be an Expr. Strings are parsed as column names. |
Value
Expr
Examples
library("polars")
df = pl$DataFrame(
s = list(1:4, c(10L, 2L, 1L)),
n = 1:2
)
df$with_columns(
tail_by_expr = pl$col("s")$list$tail("n"),
tail_by_lit = pl$col("s")$list$tail(2)
)
#> shape: (2, 4)
#> ┌─────────────┬─────┬──────────────┬─────────────┐
#> │ s ┆ n ┆ tail_by_expr ┆ tail_by_lit │
#> │ --- ┆ --- ┆ --- ┆ --- │
#> │ list[i32] ┆ i32 ┆ list[i32] ┆ list[i32] │
#> ╞═════════════╪═════╪══════════════╪═════════════╡
#> │ [1, 2, … 4] ┆ 1 ┆ [4] ┆ [3, 4] │
#> │ [10, 2, 1] ┆ 2 ┆ [2, 1] ┆ [2, 1] │
#> └─────────────┴─────┴──────────────┴─────────────┘