Add items2dict filter that is the reverse of dict2items (#42071)

* Add items2dict filter that is the reverse of dict2items

* Address feedback about type checking, and add docs for zip/zip_longest
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Matt Martz 2018-06-29 10:47:07 -05:00 committed by GitHub
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2 changed files with 84 additions and 16 deletions

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@ -184,6 +184,77 @@ into::
- key: Environment
value: dev
items2dict filter
`````````````````
.. versionadded:: 2.7
This filter turns a list of dicts with 2 keys, into a dict, mapping the values of those keys into ``key: value`` pairs::
{{ tags | items2dict }}
Which turns::
tags:
- key: Application
value: payment
- key: Environment
value: dev
into::
Application: payment
Environment: dev
This is the reverse of the ``dict2items`` filter.
``items2dict`` accepts 2 keyword arguments, ``key_name`` and ``value_name`` that allow configuration of the names of the keys to use for the transformation::
{{ tags | items2dict(key_name='key', value_name='value') }}
.. _zip_filter:
zip and zip_longest filters
```````````````````````````
.. versionadded:: 2.3
To get a list combining the elements of other lists use ``zip``::
- name: give me list combo of two lists
debug:
msg: "{{ [1,2,3,4,5]|zip(['a','b','c','d','e','f'])|list }}"
- name: give me shortest combo of two lists
debug:
msg: "{{ [1,2,3]|zip(['a','b','c','d','e','f'])|list }}"
To always exhaust all list use ``zip_longest``::
- name: give me longest combo of three lists , fill with X
debug:
msg: "{{ [1,2,3]|zip_longest(['a','b','c','d','e','f'], [21, 22, 23], fillvalue='X')|list }}"
Similarly to the output of the ``items2dict`` filter mentioned above, these filters can be used to contruct a ``dict``::
{{ dict(keys_list | zip(values_list)) }}
Which turns::
list_one:
- one
- two
list_two:
- apple
- orange
into::
one: apple
two: orange
subelements Filter
``````````````````
@ -1074,22 +1145,7 @@ Combinations always require a set size::
msg: "{{ [1,2,3,4,5]|combinations(2)|list }}"
To get a list combining the elements of other lists use ``zip``::
- name: give me list combo of two lists
debug:
msg: "{{ [1,2,3,4,5]|zip(['a','b','c','d','e','f'])|list }}"
- name: give me shortest combo of two lists
debug:
msg: "{{ [1,2,3]|zip(['a','b','c','d','e','f'])|list }}"
To always exhaust all list use ``zip_longest``::
- name: give me longest combo of three lists , fill with X
debug:
msg: "{{ [1,2,3]|zip_longest(['a','b','c','d','e','f'], [21, 22, 23], fillvalue='X')|list }}"
Also see the :ref:`zip_filter`
.. versionadded:: 2.4