Question:
I’d like to remove an item from a list, based on another list.
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"my_list_one": [ "item1", "item2", "item3" ] |
My second list:
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"my_list_two": [ "item3" ] |
How do I remove ‘item3’ from this list, to set a new fact?
I tried using ‘-‘ and union, but this does not end in the desired end result.
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set_fact: my_list_one: "{{ my_list_one | union(my_list_two) }}" |
End goal:
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"my_list_one": [ "item1", "item2" ] |
Answer:
Use difference not union:
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{{ my_list_one | difference(my_list_two) }} |
An example playbook (note that you must also provide variable name to set_fact):
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--- - hosts: localhost connection: local vars: my_list_one: - item1 - item2 - item3 my_list_two: - item3 tasks: - set_fact: my_list_one: "{{ my_list_one | difference(my_list_two) }}" - debug: var=my_list_one |
The result (excerpt):
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TASK [debug] ******************************************************************* ok: [localhost] => { "my_list_one": [ "item1", "item2" ] } |