unpacklist

Introduction

Use the unpacklist instruction to separate lists contained in a single column of a data extract into separate rows within a newly created column. This transformation can also unpack a list of lists.

Before you unpack the lists, run the convertx transformation with the following Python expression:

__import__('ast').literal_eval({FIELD})

Replace FIELD with the name of the column that contains the lists. Running this transformation enables Adverity to read the lists. For more information, see the Python documentation.

When to use this instruction

Use unpacklist when:

• You want to explode lists in a column into multiple rows, for example one row per ID or tag in a list.

• You are preparing data for joins or aggregations where each list element should be treated as an individual record.

If you instead want each list position to become its own column, use unpack instead.

Creating a custom script transformation using the unpacklist instruction

To create and configure a custom script using the unpacklist instruction, follow these steps:

1. Create a custom script transformation.

2. In the Instruction step, select the unpacklist instruction.

3. To configure the custom script instruction, fill in the following fields. Required fields are marked with an asterisk (*).

Field

Enter the name of the column that contains the lists.

Newfield

Enter the name of the new column that is to be added to the data extract. Adverity populates this column with the list items.

Include Original

Select this checkbox to keep the column that contains the lists in the data extract.

Subtable

Enter the name for a subtable that you want to use within this custom script.

A subtable is a temporary table that only exists for this custom script. You can apply additional instructions within the same custom script to the subtable. However, the subtable cannot be used in any other custom scripts.

If a subtable does not exist for the current custom script, the transformation is applied to the data extract, and the enriched data is output into the subtable. If the subtable already exists for the custom script, the subtable is used as the input for the transformation and optionally as the output.

Example