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+[//]: # (title: update)
+
+<!---IMPORT org.jetbrains.kotlinx.dataframe.samples.api.Modify-->
+
+Returns [`DataFrame`](DataFrame.md) with changed values in some cells. Column types can not be changed.
+
+```text
+update { columns }
+    [.where { rowCondition } ]
+    [.at(rowIndices) ] 
+     .with { rowExpression } | .notNull { rowExpression } | .perCol { colExpression } | .perRowCol { rowColExpression } | .withNull() | .withZero() | .asFrame { frameExpression } 
+
+rowCondition: DataRow.(OldValue) -> Boolean
+rowExpression: DataRow.(OldValue) -> NewValue
+colExpression: DataColumn.(DataColumn) -> NewValue
+rowColExpression: (DataRow, DataColumn) -> NewValue
+frameExpression: DataFrame.(DataFrame) -> DataFrame
+```
+
+**Related operations**: [](updateConvert.md)
+
+See [column selectors](ColumnSelectors.md) for how to select the columns for this operation and
+[row expressions](DataRow.md#row-expressions) for how to specify the new values.
+
+<!---FUN update-->
+
+```kotlin
+df.update { age }.with { it * 2 }
+df.update { colsAtAnyDepth().colsOf<String>() }.with { it.uppercase() }
+df.update { weight }.at(1..4).notNull { it / 2 }
+df.update { name.lastName and age }.at(1, 3, 4).withNull()
+```
+
+<inline-frame src="resources/org.jetbrains.kotlinx.dataframe.samples.api.Modify.update.html" width="100%"/>
+<!---END-->
+
+Update with constant value:
+
+<!---FUN updateWithConst-->
+
+```kotlin
+df.update { city }.where { name.firstName == "Alice" }.with { "Paris" }
+```
+
+<inline-frame src="resources/org.jetbrains.kotlinx.dataframe.samples.api.Modify.updateWithConst.html" width="100%"/>
+<!---END-->
+
+Update with value depending on row:
+
+<!---FUN updateWith-->
+
+```kotlin
+df.update { city }.with { name.firstName + " from " + it }
+```
+
+<inline-frame src="resources/org.jetbrains.kotlinx.dataframe.samples.api.Modify.updateWith.html" width="100%"/>
+<!---END-->
+
+Update with value depending on column:
+
+<!---FUN updatePerColumn-->
+
+```kotlin
+df.update { colsOf<Number?>() }.perCol { mean(skipNaN = true) }
+```
+
+<!---END-->
+
+Update with value depending on row and column:
+
+<!---FUN updatePerRowCol-->
+
+```kotlin
+df.update { colsOf<String?>() }.perRowCol { row, col -> col.name() + ": " + row.index() }
+```
+
+<inline-frame src="resources/org.jetbrains.kotlinx.dataframe.samples.api.Modify.updatePerRowCol.html" width="100%"/>
+<!---END-->
+
+Update [ColumnGroup](DataColumn.md#columngroup) as [DataFrame](DataFrame.md):
+
+<!---FUN updateAsFrame-->
+
+```kotlin
+df.update { name }.asFrame { select { lastName } }
+```
+
+<inline-frame src="resources/org.jetbrains.kotlinx.dataframe.samples.api.Modify.updateAsFrame.html" width="100%"/>
+<!---END-->