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Iso-Year

Source code

Description

Extract ISO year from underlying Date representation. Applies to Date and Datetime columns. Returns the year number in the ISO standard. This may not correspond with the calendar year.

Usage

<Expr>$dt$iso_year()

Value

Expr of iso_year as Int32

Examples

library("polars")

df = pl$DataFrame(
  date = pl$date_range(
    as.Date("2020-12-25"),
    as.Date("2021-1-05"),
    interval = "1d",
    time_zone = "GMT"
  )
)
df$with_columns(
  pl$col("date")$dt$year()$alias("year"),
  pl$col("date")$dt$iso_year()$alias("iso_year")
)

#> shape: (12, 3)
#> ┌────────────┬──────┬──────────┐
#> │ date       ┆ year ┆ iso_year │
#> │ ---        ┆ ---  ┆ ---      │
#> │ date       ┆ i32  ┆ i32      │
#> ╞════════════╪══════╪══════════╡
#> │ 2020-12-25 ┆ 2020 ┆ 2020     │
#> │ 2020-12-26 ┆ 2020 ┆ 2020     │
#> │ 2020-12-27 ┆ 2020 ┆ 2020     │
#> │ 2020-12-28 ┆ 2020 ┆ 2020     │
#> │ 2020-12-29 ┆ 2020 ┆ 2020     │
#> │ …          ┆ …    ┆ …        │
#> │ 2021-01-01 ┆ 2021 ┆ 2020     │
#> │ 2021-01-02 ┆ 2021 ┆ 2020     │
#> │ 2021-01-03 ┆ 2021 ┆ 2020     │
#> │ 2021-01-04 ┆ 2021 ┆ 2021     │
#> │ 2021-01-05 ┆ 2021 ┆ 2021     │
#> └────────────┴──────┴──────────┘