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Fills the string with zeroes.

Description

Add zeroes to a string until it reaches n characters. If the number of characters is already greater than n, the string is not modified.

Usage

<Expr>$str$zfill(length)

Arguments

length Pad the string until it reaches this length. Strings with length equal to or greater than this value are returned as-is. This can be an Expr or something coercible to an Expr. Strings are parsed as column names.

Details

Return a copy of the string left filled with ASCII ‘0’ digits to make a string of length width.

A leading sign prefix (‘+’/‘-’) is handled by inserting the padding after the sign character rather than before. The original string is returned if width is less than or equal to len(s).

Value

A polars expression

Examples

library("polars")

df <- pl$DataFrame(a = c(-1L, 123L, 999999L, NA))
df$with_columns(zfill = pl$col("a")$cast(pl$String)$str$zfill(4))

#> shape: (4, 2)
#> ┌────────┬────────┐
#> │ a      ┆ zfill  │
#> │ ---    ┆ ---    │
#> │ i32    ┆ str    │
#> ╞════════╪════════╡
#> │ -1     ┆ -001   │
#> │ 123    ┆ 0123   │
#> │ 999999 ┆ 999999 │
#> │ null   ┆ null   │
#> └────────┴────────┘