polars_xdt.ExprXDTNamespace.to_local_datetime

ExprXDTNamespace.to_local_datetime(time_zone: str | Expr) → XDTExpr

Convert to local datetime in given time zone.

Parameters:

time_zone

Time zone to convert to.

Returns:

Expr

Expression of data type DateTime.

Examples

You can use to_local_datetime to figure out how a tz-aware datetime will be expressed as a local datetime.

>>> from datetime import datetime
>>> import polars_xdt  # noqa: F401
>>> df = pl.DataFrame(
...     {
...         "date_col": [datetime(2020, 10, 10)] * 3,
...         "timezone": [
...             "Europe/London",
...             "Africa/Kigali",
...             "America/New_York",
...         ],
...     }
... ).with_columns(pl.col("date_col").dt.replace_time_zone("UTC"))
>>> df.with_columns(
...     pl.col("date_col")
...     .xdt.to_local_datetime(pl.col("timezone"))
...     .alias("local_dt")
... )
shape: (3, 3)
┌─────────────────────────┬──────────────────┬─────────────────────┐
│ date_col                ┆ timezone         ┆ local_dt            │
│ ---                     ┆ ---              ┆ ---                 │
│ datetime[μs, UTC]       ┆ str              ┆ datetime[μs]        │
╞═════════════════════════╪══════════════════╪═════════════════════╡
│ 2020-10-10 00:00:00 UTC ┆ Europe/London    ┆ 2020-10-10 01:00:00 │
│ 2020-10-10 00:00:00 UTC ┆ Africa/Kigali    ┆ 2020-10-10 02:00:00 │
│ 2020-10-10 00:00:00 UTC ┆ America/New_York ┆ 2020-10-09 20:00:00 │
└─────────────────────────┴──────────────────┴─────────────────────┘