polars.Expr.dt.second#

Expr.dt.second(*, fractional: bool = False) → Expr[source]#

Extract seconds from underlying DateTime representation.

Applies to Datetime columns.

Returns the integer second number from 0 to 59, or a floating point number from 0 < 60 if fractional=True that includes any milli/micro/nanosecond component.

Parameters:

fractional: Whether to include the fractional component of the second.

Returns:

Expr: Expression of data type Int8 or Float64.

Examples

>>> from datetime import datetime
>>> df = pl.DataFrame(
...     {
...         "datetime": [
...             datetime(1978, 1, 1, 1, 1, 1, 0),
...             datetime(2024, 10, 13, 5, 30, 14, 500_000),
...             datetime(2065, 1, 1, 10, 20, 30, 60_000),
...         ]
...     }
... )
>>> df.with_columns(
...     pl.col("datetime").dt.hour().alias("hour"),
...     pl.col("datetime").dt.minute().alias("minute"),
...     pl.col("datetime").dt.second().alias("second"),
... )
shape: (3, 4)
┌─────────────────────────┬──────┬────────┬────────┐
│ datetime                ┆ hour ┆ minute ┆ second │
│ ---                     ┆ ---  ┆ ---    ┆ ---    │
│ datetime[μs]            ┆ i8   ┆ i8     ┆ i8     │
╞═════════════════════════╪══════╪════════╪════════╡
│ 1978-01-01 01:01:01     ┆ 1    ┆ 1      ┆ 1      │
│ 2024-10-13 05:30:14.500 ┆ 5    ┆ 30     ┆ 14     │
│ 2065-01-01 10:20:30.060 ┆ 10   ┆ 20     ┆ 30     │
└─────────────────────────┴──────┴────────┴────────┘
>>> df.with_columns(
...     pl.col("datetime").dt.hour().alias("hour"),
...     pl.col("datetime").dt.minute().alias("minute"),
...     pl.col("datetime").dt.second(fractional=True).alias("second"),
... )
shape: (3, 4)
┌─────────────────────────┬──────┬────────┬────────┐
│ datetime                ┆ hour ┆ minute ┆ second │
│ ---                     ┆ ---  ┆ ---    ┆ ---    │
│ datetime[μs]            ┆ i8   ┆ i8     ┆ f64    │
╞═════════════════════════╪══════╪════════╪════════╡
│ 1978-01-01 01:01:01     ┆ 1    ┆ 1      ┆ 1.0    │
│ 2024-10-13 05:30:14.500 ┆ 5    ┆ 30     ┆ 14.5   │
│ 2065-01-01 10:20:30.060 ┆ 10   ┆ 20     ┆ 30.06  │
└─────────────────────────┴──────┴────────┴────────┘