polars_xdt.month_delta

polars_xdt.month_delta(start_dates: IntoExpr, end_dates: IntoExpr) → pl.Expr

Calculate the number of months between two Series.

Parameters:

start_dates

A Series object containing the start dates.

end_dates

A Series object containing the end dates.

Returns:

polars.Expr

Examples

>>> from datetime import date
>>> import polars as pl
>>> import polars_xdt as xdt
>>> df = pl.DataFrame(
...     {
...         "start_date": [
...             date(2024, 3, 1),
...             date(2024, 3, 31),
...             date(2022, 2, 28),
...             date(2023, 1, 31),
...             date(2019, 12, 31),
...         ],
...         "end_date": [
...             date(2023, 2, 28),
...             date(2023, 2, 28),
...             date(2023, 2, 28),
...             date(2023, 1, 31),
...             date(2023, 1, 1),
...         ],
...     },
... )
>>> df.with_columns(
...     xdt.month_delta("start_date", "end_date").alias("month_delta")
... )
shape: (5, 3)
┌────────────┬────────────┬─────────────┐
│ start_date ┆ end_date   ┆ month_delta │
│ ---        ┆ ---        ┆ ---         │
│ date       ┆ date       ┆ i32         │
╞════════════╪════════════╪═════════════╡
│ 2024-03-01 ┆ 2023-02-28 ┆ -12         │
│ 2024-03-31 ┆ 2023-02-28 ┆ -13         │
│ 2022-02-28 ┆ 2023-02-28 ┆ 12          │
│ 2023-01-31 ┆ 2023-01-31 ┆ 0           │
│ 2019-12-31 ┆ 2023-01-01 ┆ 36          │
└────────────┴────────────┴─────────────┘