Is there a difference in specifying hosts as a list vs specifying hosts as comma separated list in playbooks ?

[ishan jain]

Playbook:

---

- hosts: "{{hostList}}"

  vars_files:

      - "{{file}}"

  tasks:

     - debug: var=inventory_hostname

Inventory

[servers]

one ansible_connection=local

two ansible_connection=local

vars.yaml (type 1)

hostList:

   - one

   - two

Result with type 1 vars (ansible-playbook -i host test.yaml  -e file=vars.yaml)

PLAY [[u'one', u'two']] *****************************************************************************************************************************************************************************

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

ok: [two]

ok: [one]

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

ok: [one] => {

    "inventory_hostname": "one"

}

ok: [two] => {

    "inventory_hostname": "two"

}

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

one                        : ok=2    changed=0    unreachable=0    failed=0

two                        : ok=2    changed=0    unreachable=0    failed=0

vars.yaml (type 2)

hostList: one, two

Now, result with type 2 vars (ansible-playbook -i host test.yaml  -e file=vars.yaml)

PLAY [one, two] *************************************************************************************************************************************************************************************

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

ok: [one]

ok: [two]

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

ok: [one] => {

    "inventory_hostname": "one"

}

ok: [two] => {

    "inventory_hostname": "two"

}

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

one                        : ok=2    changed=0    unreachable=0    failed=0

two                        : ok=2    changed=0    unreachable=0    failed=0

The only difference between specifying the host list as comma separated list and as a proper list is this line at the start:

PLAY [[u'one', u'two']] *****************************************************************************************************************************************************************************

Though everything runs fine, i am just curious about the differences between the two ways of specifying hosts.