Get the group indexes of the group by operation

Description

Usage

<Expr>$agg_groups()

Details

agg_groups() is deprecated as of polars 1.16.0. Use df$with_row_index()$group_by(…, .maintain_order = TRUE)$agg(pl$col(“index”)) instead.

Should be used in aggregation context only.

Value

A polars expression

Examples

library("polars")

df <- pl$DataFrame(
  group = rep(c("one", "two"), each = 3),
  value = c(94, 95, 96, 97, 97, 99)
)

df$group_by("group", .maintain_order = TRUE)$agg(pl$col("value")$agg_groups())

#> shape: (2, 2)
#> ┌───────┬───────────┐
#> │ group ┆ value     │
#> │ ---   ┆ ---       │
#> │ str   ┆ list[u32] │
#> ╞═══════╪═══════════╡
#> │ one   ┆ [0, 1, 2] │
#> │ two   ┆ [3, 4, 5] │
#> └───────┴───────────┘

# Recommended approach
df$with_row_index()$group_by("group", .maintain_order = TRUE)$agg(pl$col("index"))

#> shape: (2, 2)
#> ┌───────┬───────────┐
#> │ group ┆ index     │
#> │ ---   ┆ ---       │
#> │ str   ┆ list[u32] │
#> ╞═══════╪═══════════╡
#> │ one   ┆ [0, 1, 2] │
#> │ two   ┆ [3, 4, 5] │
#> └───────┴───────────┘