jschon 0.7.1

A pythonic, extensible JSON Schema implementation.

jschon

jschon is a pythonic and extensible implementation of the JSON Schema specification.

Features

• JSON Schema 2019-09 and 2020-12 vocabulary implementations
• Support for custom metaschemas, vocabularies and format validators
• JSON class implementing the JSON data model
• JSON pointer implementation (RFC 6901)

Installation

pip install jschon

Hello World Example

from jschon import create_catalog, JSON, JSONSchema
from pprint import pp

create_catalog('2020-12', default=True)

schema = JSONSchema({
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "$id": "https://example.com/greeting",
    "type": "object",
    "properties": {
        "greeting": {"$ref": "#/$defs/greetingDefinition"}
    },
    "$defs": {
        "greetingDefinition": {
            "type": "string",
            "minLength": 10
        }
    }
})

valid_instance = JSON({
    "greeting": "Hello, World!"
})

invalid_instance = JSON({
    "greeting": "Hi, World"
})

pp(schema.evaluate(valid_instance).valid)
# True

pp(schema.evaluate(invalid_instance).output('detailed'))
# {'valid': False,
#  'instanceLocation': '',
#  'keywordLocation': '',
#  'absoluteKeywordLocation': 'https://example.com/greeting#',
#  'errors': [{'instanceLocation': '/greeting',
#              'keywordLocation': '/properties/greeting/$ref/minLength',
#              'absoluteKeywordLocation': 'https://example.com/greeting#/$defs/greetingDefinition/minLength',
#              'error': 'The text is too short (minimum 10 characters)'}]}

Documentation

Further examples, as well as a user guide and API reference, are available at Read the Docs.

Testing

jschon is tested using the JSON Schema Test Suite (excluding optional and format tests), along with custom unit tests that make use of the Hypothesis testing library.

To run the tests, install jschon in editable mode, including testing dependencies:

pip install -e git+https://github.com/marksparkza/jschon.git#egg=jschon[test]

Then, cd to the jschon source directory (pip show jschon will give you the location), and type tox.

Note that a complete test run requires all of the supported Python versions (3.8, 3.9, 3.10) to be installed on your system.

Contributing

Please see the guidelines for contributing.