DOCUMENTATION:
  name: extract
  version_added: "2.1"
  short_description: extract a value based on an index or key
  description:
    - Extract a value from a list or dictionary based on an index/key.
    - User must ensure that index or key used matches the type of container.
    - Equivalent of using C(list[index]) and C(dictionary[key]) but useful as a filter to combine with C(map).
  positional: _input, container, morekeys
  options:
    _input:
      description: Index or key to extract.
      type: raw
      required: true
    container:
      description: Dictionary or list from which to extract a value.
      type: raw
      required: true
    morekeys:
      description: Indicies or keys to extract from the initial result (subkeys/subindices).
      type: list
      elements: dictionary
      required: true

EXAMPLES: |

    # extracted => 'b', same as ['a', 'b', 'c'][1]
    extracted: "{{ 1 | extract(['a', 'b', 'c']) }}"

    # extracted_key => '2', same as {'a': 1, 'b': 2, 'c': 3}['b']
    extracted_key: "{{ 'b' | extract({'a': 1, 'b': 2, 'c': 3}) }}"

    # extracted_key_r => '2', same as [{'a': 1, 'b': 2, 'c': 3}, {'x': 9, 'y': 10}][0]['b']
    extracted_key_r: "{{ 0 | extract([{'a': 1, 'b': 2, 'c': 3}, {'x': 9, 'y': 10}], morekeys='b') }}"

RETURN:
  _value:
    description: Resulting merge of supplied dictionaries.
    type: dict