How to get interpolated value of variable in Ansible / Jinja2 - ansible

Question

I'm trying to define Ansible variables this way:
user:
name: First Last
nick: '{{ vars["user"]["name"] | regex_replace("\W", "_") }}'
email: '{{ vars["user"]["nick"] }}#example.com'
And the result email is: "{{ vars[\"user\"][\"name\"] | regex_replace(\"\\W\", \"_\") }}#example.com.
I also tried to set email like this: {{ lookup("vars", "user.nick") }}#example.com or {{ lookup("vars", "user")["nick"] }}#example.com, and it says An unhandled exception occurred while running the lookup plugin 'vars'.
Is there a way to get resulting variable values as:
user:
name: First Last
nick: First_Last
email: First_Last#example.com
?
ansible 2.9.10,
python version = 3.8.5

Answer 1

It's not possible cross-reference keys in a dictionary. It's necessary to declare the variables outside the dictionary. For example, the playbook
- hosts: localhost
vars:
my_name: First Last
my_nick: "{{ my_name | regex_replace('\\W', '_') }}"
user:
name: "{{ my_name }}"
nick: "{{ my_nick }}"
email: "{{ my_nick }}#example.com"
tasks:
- debug:
var: user
gives (abridged)
user:
email: First_Last#example.com
name: First Last
nick: First_Last
A more flexible option is to create the variables in the loop. For example, the playbook
- hosts: localhost
vars:
users:
"First Last":
domain: example.com
tasks:
- debug:
msg:
- "name: {{ name }}"
- "nick: {{ nick }}"
- "email: {{ email }}"
loop: "{{ users|dict2items }}"
vars:
name: "{{ item.key }}"
nick: "{{ item.key|regex_replace('\\W', '_') }}"
email: "{{ nick ~ '#' ~ item.value.domain }}"
gives (abridged)
msg:
- 'name: First Last'
- 'nick: First_Last'
- 'email: First_Last#example.com'