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

GroupClause

class GroupClause<T, C>(val df: DataFrame<T>, val columns: ColumnsSelector<T, C>)

An intermediate class used in the group operation.

This class itself does nothing—it is just a transitional step before specifying how to group the selected columns. It must be followed by one of the positioning methods to produce a new DataFrame with the updated column structure.

Use the following methods to finalize the grouping:

into(groupName) – groups selected columns into a single column group.
into { groupNameExpression } – groups each column into a group by specifying path or name.

See Grammar for more details.

Constructors

GroupClause

constructor(df: DataFrame<T>, columns: ColumnsSelector<T, C>)

Properties

columns

internal val columns: ColumnsSelector<T, C>

internal val df: DataFrame<T>

Functions

into

@JvmName(name = "intoString")

fun <T, C> GroupClause<T, C>.into(column: ColumnsSelectionDsl<T>.(ColumnWithPath<C>) -> String): DataFrame<T>

Groups columns, previously selected with group, into new or existing column groups within the DataFrame, using a ColumnsSelectionDsl expression to specify the target group name for each column. The expression is applied to each selected column and determines the name of the column group it will be placed into.

@JvmName(name = "intoColumn")

fun <T, C> GroupClause<T, C>.into(column: ColumnsSelectionDsl<T>.(ColumnWithPath<C>) -> ColumnReference<*>): DataFrame<T>

Groups columns, previously selected with group, into a new or existing column group within the DataFrame by specifying its path via ColumnsSelectionDsl expression.

fun <T, C> GroupClause<T, C>.into(column: String): DataFrame<T>

Groups columns, previously selected with group, into a new or existing column group within the DataFrame, by specifying its name.

fun <T, C> GroupClause<T, C>.~~into~~(column: KProperty<*>): DataFrame<T>

fun <T, C> GroupClause<T, C>.~~into~~(column: ColumnAccessor<DataRow<*>>): DataFrame<T>

toString

open override fun toString(): String