title: Ansible - how to split a list into two lists?
body: <p>I searched and tried every way to split a list into two lists.
  There were no conventional filters or anything supported.
  There were examples and posts about combining lists into one, but not the other way around.</p>
  
  <p>I developed below code but it does not work with very strange reason, list does not have attribute 0?</p>
  
  <pre><code>---
  - hosts: localhost
    gather_facts: no
    vars:
      - listA: ['a','b','c','d']
      - listB: []
      - listC: []
  
    tasks:
    - block:
        - debug:
            var: listA[0]
        - debug:
            var: listB
        - debug:
            var: listC
    - set_fact:
        listB: "{{ listB + [listA[item]] }}"
      with_sequence: start=0 end=3 stride=2
    - set_fact:
        listC: "{{ listC + [listA[item]] }}"
      with_sequence: start=1 end=3 stride=2
  
    - block:
        - debug:
            var: listA
        - debug:
            var: listB
        - debug:
            var: listC
  </code></pre>
  
  <p>This is the test run outcome with Ansible 2.1.1.0</p>
  
  <pre><code>$ ansible-playbook test_sequenceeasy.yml
  [WARNING]: log file at '{{planfile | dirname}}/AnsibleLog.txt' is not writeable and we cannot create it, aborting
  
  
  PLAY [localhost] ***************************************************************
  
  TASK [debug] *******************************************************************
  ok: [localhost] =&gt; {
      "listA[0]": "a"
  }
  
  TASK [debug] *******************************************************************
  ok: [localhost] =&gt; {
      "listB": []
  }
  
  TASK [debug] *******************************************************************
  ok: [localhost] =&gt; {
      "listC": []
  }
  
  TASK [set_fact] ****************************************************************
  fatal: [localhost]: FAILED! =&gt; {"failed": true, "msg": "the field 'args' has an invalid value, which appears to include a variable that is undefined. The error was: 'list object' has no attribute u'0'\n\nThe error appears to have been in '/apps/infra/Tools/Ansible_WLNMiddleware/test_sequenceeasy.yml': line 17, column 5, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n          var: listC\n  - set_fact:\n    ^ here\n"}
  
  NO MORE HOSTS LEFT *************************************************************
   [WARNING]: Could not create retry file 'test_sequenceeasy.retry'.         [Errno 2] No such file or directory: ''
  </code></pre>