execution output

[vdo023@localhost jinja2-map]$ ansible-playbook -i "localhost," ./j2-map-playbook.yml

PLAY [localhost] **********************************************************************************************************************************

TASK [establish the first name from the mps dictionary] *******************************************************************************************
ok: [localhost] => {
    "msg": [
        "Tony",
        "Theresa",
        "Nigel"
    ]
}

TASK [establish the last name from the mps dictionary] ********************************************************************************************
ok: [localhost] => {
    "msg": [
        "Blair",
        "May",
        "Farage"
    ]
}

TASK [change to UPPER CASE from the mps dictionary] ***********************************************************************************************
ok: [localhost] => {
    "msg": [
        "{U'PARTY': U'LABOUR', U'FIRST_NAME': U'TONY', U'LAST_NAME': U'BLAIR'}",
        "{U'PARTY': U'CONSERVATIVE', U'FIRST_NAME': U'THERESA', U'LAST_NAME': U'MAY'}",
        "{U'PARTY': U'UKIP', U'FIRST_NAME': U'NIGEL', U'LAST_NAME': U'FARAGE'}"
    ]
}

TASK [change last name to UPPER CASE from the mps dictionary] *************************************************************************************
ok: [localhost] => {
    "msg": [
        "BLAIR",
        "MAY",
        "FARAGE"
    ]
}

j2-map-playbook.yml

- hosts: localhost
  connection: local
  gather_facts: no
  vars:
    mps:
      - first_name: Tony
        last_name: Blair
        party: labour
      - first_name: Theresa
        last_name: May
        party: conservative
      - first_name: Nigel
        last_name: Farage
        party: UKIP
  tasks:
    - name: establish the first name from the mps dictionary
      debug: msg={{ mps | map(attribute='first_name') | list }}
    - name: establish the last name from the mps dictionary
      debug: msg={{ mps | map(attribute='last_name') | list }}
    - name: change to UPPER CASE from the mps dictionary
      debug: msg={{ mps | map('upper') | list }}
    - name: change last name to UPPER CASE from the mps dictionary
      debug: msg={{ mps | map(attribute='last_name') | map('upper') | list }}