jsonschema¶
jsonschema
is an implementation of the JSON Schema specification for Python.
>>> from jsonschema import validate
>>> # A sample schema, like what we'd get from json.load()
>>> schema = {
... "type" : "object",
... "properties" : {
... "price" : {"type" : "number"},
... "name" : {"type" : "string"},
... },
... }
>>> # If no exception is raised by validate(), the instance is valid.
>>> validate(instance={"name" : "Eggs", "price" : 34.99}, schema=schema)
>>> validate(
... instance={"name" : "Eggs", "price" : "Invalid"}, schema=schema,
... )
Traceback (most recent call last):
...
ValidationError: 'Invalid' is not of type 'number'
It can also be used from the command line by installing check-jsonschema.
Features¶
Full support for Draft 2020-12, Draft 2019-09, Draft 7, Draft 6, Draft 4 and Draft 3
Lazy validation that can iteratively report all validation errors.
Programmatic querying of which properties or items failed validation.
Installation¶
jsonschema
is available on PyPI. You can install using pip:
$ pip install jsonschema
Extras¶
Two extras are available when installing the package, both currently related to format
validation:
format
format-nongpl
They can be used when installing in order to include additional dependencies, e.g.:
$ pip install jsonschema'[format]'
Be aware that the mere presence of these dependencies – or even the specification of format
checks in a schema – do not activate format checks (as per the specification).
Please read the format validation documentation for further details.
Running the Test Suite¶
If you have nox
installed (perhaps via pipx install nox
or your package manager), running nox
in the directory of your source checkout will run jsonschema
’s test suite on all of the versions of Python jsonschema
supports.
If you don’t have all of the versions that jsonschema
is tested under, you’ll likely want to run using nox
’s --no-error-on-missing-interpreters
option.
Of course you’re also free to just run the tests on a single version with your favorite test runner.
The tests live in the jsonschema.tests
package.
Benchmarks¶
jsonschema
’s benchmarks make use of pyperf.
Running them can be done via:
$ nox -s perf
Community¶
The JSON Schema specification has a Slack, with an invite link on its home page. Many folks knowledgeable on authoring schemas can be found there.
Otherwise, opening a GitHub discussion or asking questions on Stack Overflow are other means of getting help if you’re stuck.
About¶
I’m Julian Berman.
jsonschema
is on GitHub.
Get in touch, via GitHub or otherwise, if you’ve got something to contribute, it’d be most welcome!
You can also generally find me on Libera (nick: Julian
) in various channels, including #python
.
If you feel overwhelmingly grateful, you can also sponsor me.
And for companies who appreciate jsonschema
and its continued support and growth, jsonschema
is also now supportable via TideLift.
Contents¶
- Schema Validation
- Handling Validation Errors
ValidationError.message
ValidationError.validator
ValidationError.validator_value
ValidationError.schema
ValidationError.relative_schema_path
ValidationError.absolute_schema_path
ValidationError.schema_path
ValidationError.relative_path
ValidationError.absolute_path
ValidationError.json_path
ValidationError.path
ValidationError.instance
ValidationError.context
ValidationError.cause
ValidationError.parent
- ErrorTrees
- best_match and relevance
- JSON (Schema) Referencing
- Creating or Extending Validator Classes
- Frequently Asked Questions
- API Reference