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This section describes how to unnest the values in an Array into separate columns in your dataset.

Source:

In the following example dataset, students took the same test three times, and their scores were stored in any array in the Scores column.

LastNameFirstNameScores
AdamsAllen[81,87,83,79]
BurnsBonnie[98,94,92,85]
CannonChris[88,81,85,78]

Transformation:

When the data is imported, you might have to re-type the Scores column as an array:

Transformation Name Change column data type
Parameter: Columns Scores
Parameter: New type Array

You can now unnest the Scores column data into separate columns:

Transformation Name Unnest Objects into columns
Parameter: Column Scores
Parameter: Parameter: Paths to elements [0]
Parameter: Parameter: Paths to elements [1]
Parameter: Parameter: Paths to elements [2]
Parameter: Parameter: Paths to elements [3]
Parameter: Remove elements from original true
Parameter: Include original column name true

In the above transformation:

  • Each path is specified in a separate row. 
    • The [x] syntax indicates that the path is the xth element of the array. 
    • The first element of an array is referenced using [0]
  • You can choose to delete the element from the original or not. Deleting the element can be a helpful way of debugging your transformation. If all of the elements are gone, then the transformation is complete. 
  • If you include the original column name in the output column names, you have some contextual information for the outputs.

Results:

LastNameFirstNameScores_0Scores_1Scores_2Scores_3
AdamsAllen81878379
BurnsBonnie98949285
CannonChris88818578

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