Nothing happens if no match is found. If the value is None the matched elements are deleted.
$key: val In case a dictionary is passed in yaml format, if looks for all items in the array dict_to_change
that are dictionaries and contains this <key> equal to <val>. Several keys can be used by yaml
- format '{key: val, key: val, ...}'; and all of them mast match. Nothing happens if no match is
+ format '{key: val, key: val, ...}'; and all of them must match. Nothing happens if no match is
found. If value is None the matched items are deleted, otherwise they are edited.
$+val If no match if found (see '$val'), the value is appended to the array. If any match is found nothing
is changed. A value of None has not sense.