rename() function

rename() renames columns in a table.

If a column in the group key is renamed, the column name in the group key is updated.

Function type signature

(<-tables: stream[B], ?columns: A, ?fn: (column: string) => string) => stream[C] where A: Record, B: Record, C: Record

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Parameters

columns

Record that maps old column names to new column names.

fn

Function that takes the current column name (column) and returns a new column name.

tables

Input data. Default is piped-forward data (<-).

Examples

• Explicitly map column names to new column names
• Rename columns using a function
• Conditionally rename columns using a function

Explicitly map column names to new column names

import "sampledata"

sampledata.int()
    |> rename(columns: {tag: "uid", _value: "val"})

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Input data

Output data

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Rename columns using a function

import "sampledata"

sampledata.int()
    |> rename(fn: (column) => "${column}_new")

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Input data

Output data

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Conditionally rename columns using a function

import "sampledata"

sampledata.int()
    |> rename(
        fn: (column) => {
            _newColumnName = if column =~ /^_/ then "${column} (Reserved)" else column

            return _newColumnName
        },
    )

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Input data

Output data

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