Operations on Polars DataFrame grouped on time or integer values

Description

This class comes from \<DataFrame>$group_by_dynamic().

Examples

library("polars")

df = pl$DataFrame(
  time = pl$datetime_range(
    start = strptime("2021-12-16 00:00:00", format = "%Y-%m-%d %H:%M:%S", tz = "UTC"),
    end = strptime("2021-12-16 03:00:00", format = "%Y-%m-%d %H:%M:%S", tz = "UTC"),
    interval = "30m"
  ),
  n = 0:6
)

# get the sum in the following hour relative to the "time" column
df$group_by_dynamic("time", every = "1h")

#> shape: (7, 2)
#> ┌─────────────────────────┬─────┐
#> │ time                    ┆ n   │
#> │ ---                     ┆ --- │
#> │ datetime[ms, UTC]       ┆ i32 │
#> ╞═════════════════════════╪═════╡
#> │ 2021-12-16 00:00:00 UTC ┆ 0   │
#> │ 2021-12-16 00:30:00 UTC ┆ 1   │
#> │ 2021-12-16 01:00:00 UTC ┆ 2   │
#> │ 2021-12-16 01:30:00 UTC ┆ 3   │
#> │ 2021-12-16 02:00:00 UTC ┆ 4   │
#> │ 2021-12-16 02:30:00 UTC ┆ 5   │
#> │ 2021-12-16 03:00:00 UTC ┆ 6   │
#> └─────────────────────────┴─────┘