Ansible when condition with "in" keyword

Task: Check the disk space of the file system When the operating system is "RedHat" or  "CentOS" or "Debian" using "when" condition and "in" keyword

[osboxes@master ansible-playbooks]$ cat conditions-in.yml

---

- name: check the disk space on the file system

  hosts: all

  vars:

    distributions:

      - RedHat

      - CentOS

      - Debian

  tasks:

    - name: Check the disk space on the each server

      shell: df -h

      register: result

    - debug:

        var: result.stdout_lines

      when: ansible_distribution in distributions

[osboxes@master ansible-playbooks]$ ansible-playbook conditions-in.yml -i inventory.txt

PLAY [check the disk space on the file system] **************************************************************************************************************

TASK [Gathering Facts] **************************************************************************************************************************************

ok: [192.168.1.182]

TASK [Check the disk space on the each server] **************************************************************************************************************

changed: [192.168.1.182]

TASK [debug] ************************************************************************************************************************************************

ok: [192.168.1.182] => {

    "result.stdout_lines": [

        "Filesystem      Size  Used Avail Use% Mounted on",

        "devtmpfs        887M     0  887M   0% /dev",

        "tmpfs           914M     0  914M   0% /dev/shm",

        "tmpfs           914M  9.2M  905M   1% /run",

        "tmpfs           914M     0  914M   0% /sys/fs/cgroup",

        "/dev/sda2       236G  6.9G  230G   3% /",

        "/dev/sda5       254G  1.9G  252G   1% /home",

        "/dev/sda1       976M  188M  722M  21% /boot",

        "tmpfs           183M  1.2M  182M   1% /run/user/42",

        "tmpfs           183M  4.0K  183M   1% /run/user/1000"

    ]

}

PLAY RECAP **************************************************************************************************************************************************

192.168.1.182              : ok=3    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0