'Jolt Transform extracting data from flattened array into object

I am having some trouble with extracting data from a flattened array. I'm flattening a JSON file then using Jolt I am preparing the data.

Having this structure:

{
  "body.places[0]_name": "Test",
  "body.places[0]_population": "72",
  "body.places[1]_name": "Demo",
  "body.places[1]_population": "182"
}

I am trying to get to:

{
  "place_test": "72"
  "place_demo": "182"
}

Has anyone got any ideas on making this work?

apache-nifijolt


Solution 1:[1]

With your unflattened input, this could have been a one-liner. Here, we have to unflatten it first.

jq '
  to_entries
  | reduce (
      group_by((.key / "_")[0])[]
      | map(.key |= (. / "_")[1])
      | from_entries
    ) as $g (
      {};
      .["place_\($g.name | ascii_downcase)"] = $g.population
    )
'

{
  "place_test": "72",
  "place_demo": "182"
}

Demo

Solution 2:[2]

Why not just:

{ place_test: .["body.places[0]_population"],
  place_demo: .["body.places[1]_population"] }

Or if that trailing comma must be dealt with:

hjson -j | jq ...

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 pmf
Solution 2 peak

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