polars.Expr.dt.with_time_unit

Expr.dt.with_time_unit(time_unit: TimeUnit) → Expr

Set time unit of an expression of dtype Datetime or Duration.

Deprecated since version 0.20.5: First cast to Int64 and then cast to the desired data type.

This does not modify underlying data, and should be used to fix an incorrect time unit.

Parameters:

time_unit{‘ns’, ‘us’, ‘ms’}

Unit of time for the Datetime or Duration expression.

Examples

>>> from datetime import datetime
>>> df = pl.DataFrame(
...     {
...         "date": pl.datetime_range(
...             datetime(2001, 1, 1),
...             datetime(2001, 1, 3),
...             "1d",
...             time_unit="ns",
...             eager=True,
...         )
...     }
... )
>>> df.select(
...     pl.col("date"),
...     pl.col("date").dt.with_time_unit("us").alias("time_unit_us"),
... )  
shape: (3, 2)
┌─────────────────────┬───────────────────────┐
│ date                ┆ time_unit_us          │
│ ---                 ┆ ---                   │
│ datetime[ns]        ┆ datetime[μs]          │
╞═════════════════════╪═══════════════════════╡
│ 2001-01-01 00:00:00 ┆ +32971-04-28 00:00:00 │
│ 2001-01-02 00:00:00 ┆ +32974-01-22 00:00:00 │
│ 2001-01-03 00:00:00 ┆ +32976-10-18 00:00:00 │
└─────────────────────┴───────────────────────┘