An example of an ansible dynamic inventory script in Python

dynamic-host.json

{
    "group001": {
        "hosts": ["host001", "host002"],
        "vars": {
            "var1": true
        },
        "children": ["group002"]
    },
    "group002": {
        "hosts": ["host003","host004"],
        "vars": {
            "var2": 500
        },
        "children":[]
    },
    "server": {
      "hosts": ["ansible-target.local"],
        "vars": {
            "ansible_ssh_private_key_file": "~/ansible-exercise-key",
            "ansible_user": "ansible"
        },
        "children":[]
    }
}