Helm Template Range

Question

i'm trying to generate a a python dictionary using a values.yaml of a helm.

The values.yaml entry is

replicator:
  targets:
    - namespace: ns1
      - { configmap: ns1cm1, entry: something.yml }
    - namespace: ns2
      - { configmap: ns2cm1, entry: ns2cm1.yml }
      - { configmap: ns2cm2, entry: ns2cm2.yml }

With that input i desire to generate the following:

{
  'ns1': [
    {'ns1cm1': [ 'something.ym' ]},
  ],

  'ns2': [
    {'ns2cm1': [ 'ns2cm1.yml' ]},
    {'ns2cm2': [ 'ns2cm2.yml' ]}
  ],
}

the ConfigMap template is:

data:
  targets.py: |
    targets = {
      {{- range $target := .Values.replicator.targets }}
        '{{ $target.namespace }}': [
          {{- range $data := .Values.replicator.targets.$target }}
            { '$data.configmap': ['$data.entry'] },
          {{- end}}
        ]
      {{- end}}
    }

But i'm getting the error Error: cannot load values.yaml: error converting YAML to JSON: did not find expected key but i don't undertand why.