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Get whether the output DataType matches a certain selector

Source code

Description

[Experimental] Get whether the output DataType matches a certain selector.

Usage

<DataTypeExpr>$matches(selector)

Arguments

selector A selector presenting the data types to match.

Value

A polars datatype expression. This is not the same as a polars expression.

Examples

library("polars")

df <- pl$DataFrame(a = 1:3)
df$select(
  a_is_string = pl$dtype_of("a")$matches(cs$string()),
  a_is_integer = pl$dtype_of("a")$matches(cs$integer()),
)

#> shape: (1, 2)
#> ┌─────────────┬──────────────┐
#> │ a_is_string ┆ a_is_integer │
#> │ ---         ┆ ---          │
#> │ bool        ┆ bool         │
#> ╞═════════════╪══════════════╡
#> │ false       ┆ true         │
#> └─────────────┴──────────────┘