Skip to main content

JSONSchema generation from Python type hints

Project description

PyPi Version Docs codecov Code style: black

3.8 3.9 3.10 3.11 3.12

jsonschema-gen is Python type hints parser which can convert function and method annotations into JSONSchema objects.

  • Pythonic classes for JSONSchema types
  • Extensive type coverage: TypedDict, Generic, NewType, etc.
  • No external dependencies

Installation

With pip and python 3.8+:

pip3 install jsonschema-gen

How to use

See the user guide for more info.

Create a parser:

from jsonschema_gen import Parser

parser = Parser(strict=True)

Generate schema for your function or method from Python type hints (see the list of supported types):

from typing import NewType

UserName = NewType('UserName', str)

class UserData:
    def get_user(self, name: UserName, active: bool = True) -> dict:
        """Get user by username."""

annotation = parser.parse_function(UserData.get_user, UserData)

The result is an annotation object with input .kwargs and output .returns. You can get a JSONSchema compatible dict using json_repr() on .kwargs:

schema = annotation.kwargs.json_repr()

The result would look like this (if converted to JSON with dumps):

{
  "type": "object",
  "title": "Get user by username.",
  "properties": {
    "name": {
      "title": "Username",
      "type": "string"
    },
    "active": {
      "type": "boolean",
      "default": true
    }
  },
  "required": [
    "name"
  ],
  "additionalProperties": false
}

Use fastjsonschema or other JSONSchema validation library to create a validator for the schema:

from fastjsonschema import compile

validator = compile(schema)
valiator({'name': 'John', 'email': 'john@dowe'})

Alternatively you can pass the whole class to the parser to get the annotation mapping:

annotations = parser.parse_class(UserData)
annotations['get_user'].kwargs.json_repr()

Compatibility

The Python type hints are vast and yet not well organized, so there could always be some data type I forgot to add here. Read the customization guide to extend the standard list of type parsers.

Some annotations cannot be converted to JSONSchema objects, for example: positional-only arguments, variable positionals, etc. There are different strategies considering these types of parameters.

Python 3.8 compatibility is so-so due to lots of features and changes made in 3.9. However, it still should support most of the functionality.

Also read about the strict mode.

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distributions

No source distribution files available for this release.See tutorial on generating distribution archives.

Built Distribution

jsonschema_gen-0.1.1-py3-none-any.whl (11.1 kB view details)

Uploaded Python 3

File details

Details for the file jsonschema_gen-0.1.1-py3-none-any.whl.

File metadata

File hashes

Hashes for jsonschema_gen-0.1.1-py3-none-any.whl
Algorithm Hash digest
SHA256 26835a130d781b5cf311ba1ef5d37532943a57bd21c7667e099410a988d34f50
MD5 8abddfe2478bd064949708d6fbfa2bb6
BLAKE2b-256 c66e7c0049f841179e0bf001a5a64536c23d4a51383f240569139d13875eb575

See more details on using hashes here.

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page