polars.Expr.dt.week#

Expr.dt.week() → Expr[source]#

Extract the week from the underlying Date representation.

Applies to Date and Datetime columns.

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

Returns:

Expr: Expression of data type Int8.

Examples

>>> from datetime import date
>>> df = pl.DataFrame(
...     {"date": [date(2001, 1, 1), date(2001, 6, 30), date(2001, 12, 27)]}
... )
>>> df.with_columns(pl.col("date").dt.week().alias("week"))
shape: (3, 2)
┌────────────┬──────┐
│ date       ┆ week │
│ ---        ┆ ---  │
│ date       ┆ i8   │
╞════════════╪══════╡
│ 2001-01-01 ┆ 1    │
│ 2001-06-30 ┆ 26   │
│ 2001-12-27 ┆ 52   │
└────────────┴──────┘