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

RenameClause

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

An intermediate class used in the rename operation.

This class itself does not perform any renaming — it is a transitional step before specifying how to rename the selected columns. It must be followed by one of the renaming methods to produce a new DataFrame with renamed columns.

The resulting columns will keep their original values and positions in the DataFrame, but their names will be changed.

Use the following methods to perform the conversion:

to(name) — renames selected columns to the specified names.
to { nameExpression } — renames selected columns using a custom expression, which takes the column and its path and returns a new name.
toCamelCase() — renames all selected columns to camelCase.

For more information: See rename on the documentation website.

See Grammar for more details.

Constructors

RenameClause

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

Properties

columns

internal val columns: ColumnsSelector<T, C>

internal val df: DataFrame<T>

Functions

into

fun <T, C> RenameClause<T, C>.~~into~~(transform: (ColumnWithPath<C>) -> String): DataFrame<T>

fun <T, C> RenameClause<T, C>.~~into~~(vararg newNames: String): DataFrame<T>

NOTE: While you can keep using 'into', we recommend using to for better readability and more natural English.

fun <T, C> RenameClause<T, C>.~~into~~(vararg newNames: KProperty<*>): DataFrame<T>

fun <T, C> RenameClause<T, C>.~~into~~(vararg newColumns: ColumnReference<*>): DataFrame<T>

renameImpl

internal fun <T, C> RenameClause<T, C>.renameImpl(newNames: Array<out String>): DataFrame<T>

internal fun <T, C> RenameClause<T, C>.renameImpl(transform: (ColumnWithPath<C>) -> String): DataFrame<T>

fun to(transform: (ColumnWithPath<C>) -> String): DataFrame<T>

Renames the columns selected with rename by applying the transform expression to each of them. This expression receives the column together with its full path (as ColumnWithPath) and must return the new name for that column. The operation preserves the original columns’ values and their positions within the DataFrame.

fun to(vararg newNames: String): DataFrame<T>

Renames the columns selected with rename to the specified newNames, preserving their values and positions within the DataFrame.

fun <T, C> RenameClause<T, C>.to(transform: (ColumnWithPath<C>) -> String): DataFrame<T>

fun <T, C> RenameClause<T, C>.to(vararg newNames: String): DataFrame<T>

Renames the columns selected with rename to the specified newNames, preserving their values and positions within the DataFrame.

toCamelCase

fun <T, C> RenameClause<T, C>.toCamelCase(): DataFrame<T>

Renames the columns, previously selected with rename to "camelCase" format.

toString

open override fun toString(): String