7.1. JMESPathSearch (jp)¶

class easydata.queries.jp.JMESPathSearch(query: str, **kwargs)[source]¶: Bases: easydata.queries.key.KeySearch

JMESPathSearch (shortcut: jp) allows you to declaratively specify how to extract elements from a JSON document. JMESPathSearch uses under the hood the amazing jmespath library.

Note

jp query works only with dict or list types. If used in a easydata model and json string is provided, then it will try to convert it to a python dict or list under the hood by using json module.

7.1.1. Examples:¶

Through this tutorial we will use following json dict:

test_dict = {
    "title": "EasyBook pro 15",
    "brand": {
        "name": "EasyData",
        "origin": "Slovenia"
    },
    "image_data": [
        {
            "zoom": "https://demo.com/img1.jpg"
        },
        {
            "zoom": "https://demo.com/img2.jpg"
        }
    ],
    "images": [
        "https://demo.com/img1.jpg",
        "https://demo.com/img2.jpg",
        "https://demo.com/img3.jpg"
    ],
    "options": [
        {
            "name": "Monitor",
            "availability": {"value": "yes"},
        },
        {
            "name": "Mouse",
            "availability": {"value": "no"},
        }
    ]
}

Lets import our easydata module first.

>>> import easydata as ed

Basic examples .. code-block:: python

>>> ed.jp('title').get(test_dict)
'EasyBook pro 15'

>>> ed.jp('brand.name').get(test_dict)
'EasyData'

Examples of list .. code-block:: python

>>> ed.jp('images[]').get(test_dict)
['https://demo.com/img1.jpg', 'https://demo.com/img2.jpg', 'https://demo.com/img3.jpg']

Examples of list and slice index .. code-block:: python

>>> ed.jp('images[0:2]').get(test_dict)
['https://demo.com/img1.jpg', 'https://demo.com/img2.jpg']

>>> ed.jp('images[:2]').get(test_dict)
['https://demo.com/img1.jpg', 'https://demo.com/img2.jpg']

>>> ed.jp('images[1:]').get(test_dict)
['https://demo.com/img2.jpg', 'https://demo.com/img3.jpg']

>>> ed.jp('images[:2]').get(test_dict)
['https://demo.com/img1.jpg', 'https://demo.com/img2.jpg']

Example of selecting single value from a list by index .. code-block:: python

>>> ed.jp('images[1]').get(test_dict)
'https://demo.com/img2.jpg'

Examples of selecting values from a dict list .. code-block:: python

>>> ed.jp('image_data[].zoom').get(test_dict)
['https://demo.com/img1.jpg', 'https://demo.com/img2.jpg']

>>> ed.jp('image_data[0].zoom').get(test_dict)
'https://demo.com/img1.jpg'

Example of list with custom dict values .. code-block:: python

>>> ed.jp('options[].{name: name, stock: availability.value}').get(test_dict)
[{'name': 'Monitor', 'stock': 'yes'}, {'name': 'Mouse', 'stock': 'no'}]

Hint

In examples above we just saw basic examples how to make JMESPath queries. On a JMESPath website you can learn how to make more advanced queries.

7.1.2. Pseudo keys¶

::values¶

::values pseudo key will ensure that only values are selected from a dictionary and returned as a list.

Example without *::values* pseudo key .. code-block:: python

>>> ed.jp('brand').get(test_dict)
{'name': 'EasyData'}

Example with *::values* pseudo key .. code-block:: python

>>> ed.jp('brand::values').get(test_dict)
['EasyData', 'Slovenia']

::keys¶

::keys pseudo key will ensure that only keys are selected from a dictionary and returned as a list.

>>> ed.jp('brand::keys').get(test_dict)
['name', 'origin']

::dict(<key>:<value>)¶

With ::dict we can convert any list of dictionary into a dictionary. ::dict must receive two parameters (key and value), which are value keys from from a list of dictionaries.

Example without *::dict* pseudo key .. code-block:: python

>>> ed.jp('options[].{name: name, stock: availability.value}').get(test_dict)
[{'name': 'Monitor', 'stock': 'yes'}, {'name': 'Mouse', 'stock': 'no'}]

Example with *::dict* pseudo key .. code-block:: python

>>> ed.jp('options[].{name: name, stock: availability.value}::dict(name:stock)').get(test_dict)
{'Monitor': 'yes', 'Mouse': 'no'}

::str¶

With ::str pseudo key we can convert selected value into a str format.

>>> ed.jp('brand::str').get(test_dict)
"{'name': 'EasyData', 'origin': 'Slovenia'}"

::str pseudo key can be even used as an extension to another pseudo key.

>>> ed.jp('brand::values-str').get(test_dict)
"['EasyData', 'Slovenia']"

-str as an extension will work with following pseudo keys: keys, values, dict.

::json¶

With ::json pseudo key we can convert selected value into a json str format.

>>> ed.jp('brand::json').get(test_dict)
'{"name": "EasyData", "origin": "Slovenia"}'

::json pseudo key can be even used as an extension to another pseudo key.

>>> ed.jp('brand::values-json').get(test_dict)
'["EasyData", "Slovenia"]'

-json as an extension will work with following pseudo keys: keys, values, dict.

::yaml¶

With ::yaml pseudo key we can convert selected value into a yaml str format.

>>> ed.jp('brand::yaml').get(test_dict)
'name: EasyData\norigin: Slovenia\n'

::yaml pseudo key can be even used as an extension to another pseudo key.

>>> ed.jp('brand::keys-yaml').get(test_dict)
'- name\n- origin\n'

-yaml as an extension will work with following pseudo keys: keys, values, dict.