core/org.jetbrains.kotlinx.dataframe.api/ConvertSchemaDsl

ConvertSchemaDsl

Dsl to customize column conversion

Example:

df.convertTo<SomeSchema> {
    // defines how to convert Int? -> String
    convert<Int?>().with { it?.toString() ?: "No input given" }
    // defines how to convert String/Char -> SomeType
    parser { SomeType(it) }
    // fill missing column `sum` with expression `a+b`
    fill { sum }.with { a + b }
}

For more information: See convertTo on the documentation website.

Inheritors

ConvertSchemaDslInternal

Functions

convert

abstract fun <A, B> convert(from: KType, to: KType, converter: (A) -> B)

Defines how to convert from: A to to: B.

convert

inline fun <reified C> ConvertSchemaDsl<*>.convert(): ConvertType<C>

Defines how to convert values of the given type C.

convertIf

abstract fun convertIf(condition: (fromType: KType, toSchema: ColumnSchema) -> Boolean, converter: ConverterScope.(Any?) -> Any?)

Advanced version of convert. If you want to define a common conversion for multiple types (or any type), or you need extra information about the target, such as its schema, use this method.

fill

inline fun <T, reified C> ConvertSchemaDsl<T>.fill(noinline columns: ColumnsSelector<T, C>): ConvertToFill<T, C>

Defines how to fill all specified columns in the destination schema that were not found in the original dataframe. All fill operations for missing columns are executed after successful conversion of matched columns, so converted values of matched columns can be safely used in with expression.

parser

inline fun <reified C> ConvertSchemaDsl<*>.parser(noinline parser: (String) -> C)

Defines how to convert String values into the given type C.