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Fill floating point null value with a fill value

Description

Fill floating point null value with a fill value

Usage

<Expr>$fill_null(value, strategy = NULL, limit = NULL)

Arguments

value Value used to fill null values. Can be missing if strategy is specified. Accepts expression input, strings are parsed as column names.
strategy Strategy used to fill null values. Must be one of “forward”, “backward”, “min”, “max”, “mean”, “zero”, “one”.
limit Number of consecutive null values to fill when using the “forward” or “backward” strategy.

Value

A polars expression

Examples

library("polars")

df <- pl$DataFrame(a = c(1, NA, 2, NaN))
df$with_columns(
  filled_null_zero = pl$col("a")$fill_null(strategy = "zero"),
  filled_null_99 = pl$col("a")$fill_null(99),
  filled_null_forward = pl$col("a")$fill_null(strategy = "forward"),
  filled_null_expr = pl$col("a")$fill_null(pl$col("a")$median())
)

#> shape: (4, 5)
#> ┌──────┬──────────────────┬────────────────┬─────────────────────┬──────────────────┐
#> │ a    ┆ filled_null_zero ┆ filled_null_99 ┆ filled_null_forward ┆ filled_null_expr │
#> │ ---  ┆ ---              ┆ ---            ┆ ---                 ┆ ---              │
#> │ f64  ┆ f64              ┆ f64            ┆ f64                 ┆ f64              │
#> ╞══════╪══════════════════╪════════════════╪═════════════════════╪══════════════════╡
#> │ 1.0  ┆ 1.0              ┆ 1.0            ┆ 1.0                 ┆ 1.0              │
#> │ null ┆ 0.0              ┆ 99.0           ┆ 1.0                 ┆ 2.0              │
#> │ 2.0  ┆ 2.0              ┆ 2.0            ┆ 2.0                 ┆ 2.0              │
#> │ NaN  ┆ NaN              ┆ NaN            ┆ NaN                 ┆ NaN              │
#> └──────┴──────────────────┴────────────────┴─────────────────────┴──────────────────┘