JSON filters and tests reference

The assertion checks use a cut-down version of the Jinja templating library. To use a filter to find an item in a list and extract it as a variable, see JSON: advanced features - filtering a list & returning a value.

Filters available

More information on the filters is available in the Jinja templating library documentation. A selection of useful filters include:

Filter	Description	Parameters
first	Returns the first item in a list
join	Joins a list into a string, e.g. list|join(", ") creates a comma separated list	String to join values with attribute - attribute to use from list objects
last	Returns the last item in a list
length	Returns the length of a list
map	Applies a filter on a sequence of objects or looks up an attribute. This is useful when dealing with lists of objects but you are really only interested in a certain value of it.	attribute - attribute to look up from list objects
reject	Filters a sequence of objects by applying a test to each object, and rejecting the objects with the test succeeding.	Test for filter (see below)
rejectattr	Filters a sequence of objects by applying a test to the specified attribute of each object, and rejecting the objects with the test succeeding.	Attribute to look up from list objects Test for filter (see below)
replace	Return a copy of the value with all occurrences of a substring replaced with a new one.
select	Filters a sequence of objects by applying a test to each object, and only selecting the objects with the test succeeding.	Test for filter (see below)
selectattr	Filters a sequence of objects by applying a test to the specified attribute of each object, and only selecting the objects with the test succeeding.	Attribute to look up from list objects Test for filter (see below)
sort	Sort an iterable	reverse - reverse sort case_sensitive - whether sorting is case sensitive attribute - attribute to sort by
unique	Returns a list of unique items from the given iterable.	case_sensitive - whether sorting is case sensitive attribute - attribute to sort by

Tests available

Tests are used as part of the filters. More information on the tests is available in the Jinja templating library documentation. A selection of useful tests include:

Test	Description
eq, equalto, ==	Equal to
ge, >=	Greater or equal to
gt, >	Greater than
le, <=	Less than or equal to
lt, <	Less than
ne, !=	Not equal to
none	Returns true if the variable is null
undefined	Returns true if the variable does not exist