localplaystub.yml

- hosts: localhost
  gather_facts: false
  tasks:
    - debug:
        msg:
          - "ITEM ({{ item|type_debug }}): {{ item }}"
          - "keys ( {{ _keys|type_debug }} ): {{ _keys }}"
      loop: " {{ _keys }} "
      vars:
        _keys: [ 'bond0.160', 'bond0.197', 'bond1' ]
# END OF YML FILE ============================================================        
        
output:
"msg": "Invalid data passed to 'loop', it requires a list, got this instead:
        [u'bond0.160', u'bond0.197', u'bond1'] . Hint: If you passed a list/dict of just one element,
        try adding wantlist=True to your lookup invocation or use q/query instead of lookup."
 
Just so I can get the loop to work, I change the loop: line to be:  
       loop: [ " {{ _keys }} " ]

output:
"msg": [
    "ITEM (unicode):  [u'bond0.160', u'bond0.197', u'bond1'] ", 
    "keys ( list ): [u'bond0.160', u'bond0.197', u'bond1']"
]

...So, _keys is already a list! What gives?