Ansible: How to combine list of dictionaries?

Question

I need help with merging List of Dictionaries. Below is a sample data of 2 dictionaries. I have tried several methods. The below json shows the sample input. While the only element that changes is the Host in the entire list of Dictionaries. I need to combine the data into a single list of dictionary to post an API call. And it is not always there will be only 4 Dictionaries part of the list.

Basically looking to group / merge the data such that the common details does not change and only new details get appended.

Input

[
        {
            "Batch_number": "Batch1",
            "Date": "20221228",
            "Host": "Host1",
            "Job_Template_ID": 7,
            "Patch_Cycle": 30,
            "Patch_Day": "Day1",
            "RRule": "INTERVAL=1;COUNT=1;FREQ=MINUTELY",
            "Recurrency": "Once",
            "Start_Time": "17:00:00",
            "Technical_Tower": "Unix",
            "Timezone": "Asia/Culcutta"
        },
        {
            "Batch_number": "Batch1",
            "Date": "20221230",
            "Host": "Host11",
            "Job_Template_ID": 7,
            "Patch_Cycle": 30,
            "Patch_Day": "Day2",
            "RRule": "INTERVAL=1;COUNT=1;FREQ=MINUTELY",
            "Recurrency": "Once",
            "Start_Time": "17:00:00",
            "Technical_Tower": "Unix",
            "Timezone": "Asia/Culcutta"
        },
        {
            "Batch_number": "Batch1",
            "Date": "20230101",
            "Host": "Host21",
            "Job_Template_ID": 7,
            "Patch_Cycle": 30,
            "Patch_Day": "Day3",
            "RRule": "INTERVAL=1;COUNT=1;FREQ=MINUTELY",
            "Recurrency": "Once",
            "Start_Time": "17:00:00",
            "Technical_Tower": "Unix",
            "Timezone": "Asia/Culcutta"
        },
        {
            "Batch_number": "Batch1",
            "Date": "20230103",
            "Host": "Host31",
            "Job_Template_ID": 7,
            "Patch_Cycle": 30,
            "Patch_Day": "Day4",
            "RRule": "INTERVAL=1;COUNT=1;FREQ=MINUTELY",
            "Recurrency": "Once",
            "Start_Time": "17:00:00",
            "Technical_Tower": "Unix",
            "Timezone": "Asia/Culcutta"
        }
    ]

Expected Output

{
            "Batch_number": "Batch1",
            "Date": "20230103",
            "Host": ["Host1","Host11","Host21","Host31"],
            "Job_Template_ID": 7,
            "Patch_Cycle": 30,
            "Patch_Day": "Day4",
            "RRule": "INTERVAL=1;COUNT=1;FREQ=MINUTELY",
            "Recurrency": "Once",
            "Start_Time": "17:00:00",
            "Technical_Tower": "Unix",
            "Timezone": "Asia/Culcutta"}

Answer 1

I managed to achieve expected output by simple combine filters.

Test playbook giving the expected result is below:

---
- name: Combine batches
  hosts: localhost
  connection: local
  vars:
    batches: >-
      [
              {
                  "Batch_number": "Batch1",
                  "Date": "20221228",
                  "Host": "Host1",
                  "Job_Template_ID": 7,
                  "Patch_Cycle": 30,
                  "Patch_Day": "Day1",
                  "RRule": "INTERVAL=1;COUNT=1;FREQ=MINUTELY",
                  "Recurrency": "Once",
                  "Start_Time": "17:00:00",
                  "Technical_Tower": "Unix",
                  "Timezone": "Asia/Culcutta"
              },
              {
                  "Batch_number": "Batch1",
                  "Date": "20221230",
                  "Host": "Host11",
                  "Job_Template_ID": 7,
                  "Patch_Cycle": 30,
                  "Patch_Day": "Day2",
                  "RRule": "INTERVAL=1;COUNT=1;FREQ=MINUTELY",
                  "Recurrency": "Once",
                  "Start_Time": "17:00:00",
                  "Technical_Tower": "Unix",
                  "Timezone": "Asia/Culcutta"
              },
              {
                  "Batch_number": "Batch1",
                  "Date": "20230101",
                  "Host": "Host21",
                  "Job_Template_ID": 7,
                  "Patch_Cycle": 30,
                  "Patch_Day": "Day3",
                  "RRule": "INTERVAL=1;COUNT=1;FREQ=MINUTELY",
                  "Recurrency": "Once",
                  "Start_Time": "17:00:00",
                  "Technical_Tower": "Unix",
                  "Timezone": "Asia/Culcutta"
              },
              {
                  "Batch_number": "Batch1",
                  "Date": "20230103",
                  "Host": "Host31",
                  "Job_Template_ID": 7,
                  "Patch_Cycle": 30,
                  "Patch_Day": "Day4",
                  "RRule": "INTERVAL=1;COUNT=1;FREQ=MINUTELY",
                  "Recurrency": "Once",
                  "Start_Time": "17:00:00",
                  "Technical_Tower": "Unix",
                  "Timezone": "Asia/Culcutta"
              }
          ]
  tasks:
    - name: Show combined batch
      debug:
        var: batches | from_json | combine | combine({'Host':batch_hosts}) | to_nice_json
      vars:
        batch_hosts: >-
          {{ batches | from_json | map(attribute='Host') }}