polars.Expr.dt.milliseconds#

Expr.dt.milliseconds() → Expr[source]#

Extract the milliseconds from a Duration type.

Returns:

Expr: Expression of data type Int64.

Examples

>>> from datetime import datetime
>>> df = pl.DataFrame(
...     {
...         "date": pl.date_range(
...             datetime(2020, 1, 1),
...             datetime(2020, 1, 1, 0, 0, 1, 0),
...             "1ms",
...             eager=True,
...         ),
...     }
... )
>>> df.select(
...     [
...         pl.col("date"),
...         pl.col("date").diff().dt.milliseconds().alias("milliseconds_diff"),
...     ]
... )
shape: (1_001, 2)
┌─────────────────────────┬───────────────────┐
│ date                    ┆ milliseconds_diff │
│ ---                     ┆ ---               │
│ datetime[μs]            ┆ i64               │
╞═════════════════════════╪═══════════════════╡
│ 2020-01-01 00:00:00     ┆ null              │
│ 2020-01-01 00:00:00.001 ┆ 1                 │
│ 2020-01-01 00:00:00.002 ┆ 1                 │
│ 2020-01-01 00:00:00.003 ┆ 1                 │
│ …                       ┆ …                 │
│ 2020-01-01 00:00:00.997 ┆ 1                 │
│ 2020-01-01 00:00:00.998 ┆ 1                 │
│ 2020-01-01 00:00:00.999 ┆ 1                 │
│ 2020-01-01 00:00:01     ┆ 1                 │
└─────────────────────────┴───────────────────┘