Extract week from underlying Date representation

Description

Returns the ISO week number starting from 1. The return value ranges from 1 to 53 (the last week of year differs across years).

Usage

<Expr>$dt$week()

Value

A polars expression

Examples

library("polars")

df <- pl$select(
  date = pl$date_range(
    as.Date("2020-12-25"),
    as.Date("2021-1-05"),
    interval = "1d"
  )
)
df$with_columns(
  week = pl$col("date")$dt$week()
)

#> shape: (12, 2)
#> ┌────────────┬──────┐
#> │ date       ┆ week │
#> │ ---        ┆ ---  │
#> │ date       ┆ i8   │
#> ╞════════════╪══════╡
#> │ 2020-12-25 ┆ 52   │
#> │ 2020-12-26 ┆ 52   │
#> │ 2020-12-27 ┆ 52   │
#> │ 2020-12-28 ┆ 53   │
#> │ 2020-12-29 ┆ 53   │
#> │ …          ┆ …    │
#> │ 2021-01-01 ┆ 53   │
#> │ 2021-01-02 ┆ 53   │
#> │ 2021-01-03 ┆ 53   │
#> │ 2021-01-04 ┆ 1    │
#> │ 2021-01-05 ┆ 1    │
#> └────────────┴──────┘