Filters

jqfilters allows to easily create filter objects, which can be applied to JSON-like dictionaries. It is based on the popular JSON parsing tool jq, so the syntax mimics jq's.

For showing both, the same JSON object will be used:

>>> person = {
...     "name": "Alice"
...     "books": [
...         {"name": "The name of the wind"},
...         {"name": "A feast for crows"},
...         {"name": "Continuous delivery"}
...     ],
...     "age": 24,
...     "location": "Lancashire"
... }

Simple Queries

We will create a filter that will return True for people living in Yorkshire.

>>> from jqfilters import Filter
>>> is_from_yorkshire = Filter(op1='.location', operator='eq', op2='Yorshire')
>>> is_from_yorkshire(person)
False

We can also apply some transformation to operands (see jqfilters.operations):

>>> from jqfilters import Filter
>>> reads_a_lot = Filter(op1='.books', transform1='len', operator='ge', op2=3)
>>> reads_a_lot(person)
True

Complex Queries

We will create a filter that will return True when any of the book name is "A game of thrones" or when the person is older than 18. As this specification is more complex, the :meth:fromConfig <jqfilters.filters.Filter.fromConfig> method will be used.

>>> specs = {
...     "op1": {
...         "op1": ".books[].name",
...         "operator": "contains",
...         "op2": "A game of thrones"
...     },
...     "operator": "or",
...     "op2": {
...         "op1": ".age",
...         "operator": "ge",
...         "op2": 18
...     }
... }
>>> adult_got_fans = Filter.fromConfig(specs)
>>> adult_got_fans(person)
True

A filter can be inspected in an easier way by just prompting it:

>>> adult_got_fans
>>> ((.books[].name - contains - A game of thrones) - or - (.age - ge - 18))