Get the index of the first occurrence of a value, or NA if it’s not found

Source code

Description

Get the index of the first occurrence of a value, or NA if it’s not found

Usage

<Expr>$index_of(element)

Arguments

element

Value to find.

Value

A polars expression

Examples

library("polars")

df <- pl$DataFrame(a = c(1, NA, 17))
df$select(
  seventeen = pl$col("a")$index_of(17),
  null = pl$col("a")$index_of(NA),
  fiftyfive = pl$col("a")$index_of(55),
)

#> shape: (1, 3)
#> ┌───────────┬──────┬───────────┐
#> │ seventeen ┆ null ┆ fiftyfive │
#> │ ---       ┆ ---  ┆ ---       │
#> │ u32       ┆ u32  ┆ u32       │
#> ╞═══════════╪══════╪═══════════╡
#> │ 2         ┆ 1    ┆ null      │
#> └───────────┴──────┴───────────┘