Extract "name" from the list of dicts in Ansible

Question

I have the following dictionary:

"dict": [ {   "name": "a",   "surname": "b" }, {   "name": "c",   "surname": "d" }, {   "name": "e",   "surname": "f" } ]

I am trying to extract just "name" values into one list like this one:

names_list: ["a","c","e"]

It should be very simple but I'm not getting the result. This is what I tried:

- set_fact: 
    names_list: "{{ dict | json_query('[*].name') }}"

and also:

- set_fact: 
    names_list: "{{ dict | map(attribute='name') | list }}"

but I'm getting either "none" or "ansible undefined".

What I'm missing here?

Thanks.

Answer 1

Short answer: Rename the variable dict.

Details: In Ansible 2.14.3, Python 3.9.16, jinja version = 3.1.2 both options work as expected

    - set_fact:
        names_list1: "{{ dict|map(attribute='name')|list }}"
        names_list2: "{{ dict|json_query('[*].name') }}"

give

  names_list1: [a, c, e]
  names_list2: [a, c, e]

But, I got the warning:

[WARNING]: Found variable using reserved name: dict

---

Example of a complete playbook for testing

- hosts: localhost

  vars:

    dict:
      - {name: a, surname: b}
      - {name: c, surname: d}
      - {name: e, surname: f}

    # names_list1: "{{ dict|map(attribute='name')|list }}"
    # names_list2: "{{ dict|json_query('[*].name') }}"
    
  tasks:

    - set_fact:
        names_list1: "{{ dict|map(attribute='name')|list }}"
        names_list2: "{{ dict|json_query('[*].name') }}"
    
    - debug:
        var: names_list1|to_yaml
    - debug:
        var: names_list2|to_yaml