Iterate over two lists with indexes in Ansible

Question

i have good knowledge at programming langage, but there's something I can't make with Ansible filters and YAML syntax. Basically, I want to iterate over array/lists and make a comparison of each elements, like that in C language :

for (i=0;i<a;i++) {
  for (j=0;j<b;j++) {
     if (array1[i]==array2[j]) {
        ....     
     }
  }
}

In my case, i'm trying to compare each attributes of two lists one by one.

Is there anyway to do it with Ansible?

Thanks in advance for your answers.

Answer 1

For example

- hosts: localhost
  vars:
    array1: [a, b, c]
    array2: [b, d, c, a]
  tasks:
    - debug:
        msg: "{{ item.0 }} == {{ item.1 }} {{ item.0 == item.1 }}"
      loop: "{{ array1|product(array2)|list }}"

gives

  msg: a == b False
  msg: a == d False
  msg: a == c False
  msg: a == a True
  msg: b == b True
  msg: b == d False
  msg: b == c False
  msg: b == a False
  msg: c == b False
  msg: c == d False
  msg: c == c True
  msg: c == a False

If you want to find indices

    - debug:
        msg: "array1[{{ array1.index(item.0) }}] ==
              array2[{{ array2.index(item.1) }}]"
      loop: "{{ array1|product(array2)|list }}"
      when: item.0 == item.1

gives

  msg: array1[0] == array2[3]
  msg: array1[1] == array2[0]
  msg: array1[2] == array2[2]