Decode a value using the provided encoding

Description

Usage

<Expr>$str$decode(encoding, ..., strict = TRUE)

Arguments

encoding Either ‘hex’ or ‘base64’.

… These dots are for future extensions and must be empty.

strict If TRUE (default), raise an error if the underlying value cannot be decoded. Otherwise, replace it with a null value.

Value

A polars expression

Examples

library("polars")

df <- pl$DataFrame(strings = c("foo", "bar", NA))
df$select(pl$col("strings")$str$encode("hex"))

#> shape: (3, 1)
#> ┌─────────┐
#> │ strings │
#> │ ---     │
#> │ str     │
#> ╞═════════╡
#> │ 666f6f  │
#> │ 626172  │
#> │ null    │
#> └─────────┘

df$with_columns(
  pl$col("strings")$str$encode("base64")$alias("base64"), # notice DataType is not encoded
  pl$col("strings")$str$encode("hex")$alias("hex") # ... and must restored with cast
)$with_columns(
  pl$col("base64")$str$decode("base64")$alias("base64_decoded")$cast(pl$String),
  pl$col("hex")$str$decode("hex")$alias("hex_decoded")$cast(pl$String)
)

#> shape: (3, 5)
#> ┌─────────┬────────┬────────┬────────────────┬─────────────┐
#> │ strings ┆ base64 ┆ hex    ┆ base64_decoded ┆ hex_decoded │
#> │ ---     ┆ ---    ┆ ---    ┆ ---            ┆ ---         │
#> │ str     ┆ str    ┆ str    ┆ str            ┆ str         │
#> ╞═════════╪════════╪════════╪════════════════╪═════════════╡
#> │ foo     ┆ Zm9v   ┆ 666f6f ┆ foo            ┆ foo         │
#> │ bar     ┆ YmFy   ┆ 626172 ┆ bar            ┆ bar         │
#> │ null    ┆ null   ┆ null   ┆ null           ┆ null        │
#> └─────────┴────────┴────────┴────────────────┴─────────────┘