ansible - example of merging lists of dicts

extras.py

# ansible_plugins/filter_plugins/extras.py
def merge_dicts(value, dict1):
    # return a merged dict
    result = {}
    result = value
    result.update(dict1)
    return result

def merge_lists_of_dicts(list1, list2):
    # return a merged list
    result = []
    if len(list1) == len(list2): 
        for index,val in enumerate(list1):
            merged_items = merge_dicts(list1[index], list2[index])
            result.append(merged_items)
    return result

class FilterModule(object):
    ''' Ansible extra jinja2 filters '''

    def filters(self):
        return {
            'merge_dicts': merge_dicts,
            'merge_lists_of_dicts': merge_lists_of_dicts,
        }

output

PLAY: ***************************************************************************

TASK [set_fact foobar=[{u'type': u'cat', u'name': u'bob', u'activity': u'catnip'}, {u'type': u'dog', u'name': u'grace', u'activity': u'fetch'}, {u'type': u'moose', u'name': u'tim', u'activity': u'bowling'}]] ***
ok: [centos66]

TASK [debug var=foobar] *********************************************************
ok: [centos66] => {
    "changed": false, 
    "foobar": [
        {
            "activity": "catnip", 
            "name": "bob", 
            "type": "cat"
        }, 
        {
            "activity": "fetch", 
            "name": "grace", 
            "type": "dog"
        }, 
        {
            "activity": "bowling", 
            "name": "tim", 
            "type": "moose"
        }
    ]
}

play.yml

---
- hosts: centos66
  vars:
    pet_details_list: 
      - {"type": "cat",   "name": "bob"  }
      - {"type": "dog",   "name": "grace"}
      - {"type": "moose", "name": "tim"  }
    pet_activity_list:
      - {"activity": "catnip",  "name" "bob"  }
      - {"activity": "fetch",   "name" "grace"}
      - {"activity": "bowling", "name" "tim"  }
  tasks:
    - set_fact:
        foobar: "{{ pet_details_list | merge_lists_of_dicts(pet_activity_list) }}"
    
    - debug: 
        var: foobar