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jmespath

how to select only objects that contain an array with more than N elements

What's the right JMESPath expression to capture only the second object in the following array (because it has more than 2 objects in its topics array):

[{
  "topics": [
    "just one"
  ]
 },
 {
  "topics": [
    "first",
    "second",
    "third"
  ]
 }
]

I want it to spit out

{
  "topics": [
    "first",
    "second",
    "third"
  ]
}

I've tried [? length(topics) > 2] but jp complains about:

SyntaxError: Invalid token: tNumber
[? length(topics) > 2]
                    ^
Solution

  • For an input:

    [{
  "topics": [
    "just one"
  ]
 },
 {
  "topics": [
    "first",
    "second",
    "third"
  ]
 }
]

    use jmesExpression:

    [?length(topics)>'2']

    to get output:

    [
  {
    "topics": [
      "first",
      "second",
      "third"
    ]
  }
]