Skip to main content

JSON decoding for Python with type hinting (PEP 484)

Project description

typedjson

License Pypi CI

JSON decoding for Python with type hinting (PEP 484).

Requirements and Restrictions

  • Python >= 3.6
  • Use non-generic or parameterized class to decode JSON.
  • Use type hints without forward references.

Features

  • Support decoding types as below:
    • primitive types like str, int, float, bool and None.
    • Union and Optional.
    • homogeneous and heterogeneous Tuple and List.
    • variable-length Tuple.
    • non-generic and parameterized dataclasses.
  • Support API like json.load and json.loads.

Example

from typing import Optional

import typedjson
from dataclasses import dataclass


@dataclass(frozen=True)
class NameJson:
    first: str
    last: Optional[str]


@dataclass(frozen=True)
class CatJson:
    id: str
    age: int
    name: Optional[NameJson]


json = {
    'id': 'test-cat',
    'age': 13,
    'name': {
        'first': 'Jiji',
    },
}

print(typedjson.decode(CatJson, json))  # Output: CatJson(id='test-cat', age=13, name=NameJson(first='Jiji', last=None))

print(typedjson.decode(CatJson, {}))  # Output: DecodingError(TypeMismatch(('id',)))

Please refer to test codes for more detail.

Contributions

Please read CONTRIBUTING.md.

TODO

  • Prohibit decoding Set and Dict explicitly.
  • Provide the API document.
  • Explain why typedjson uses undocumented APIs.
  • Explain what typedjson resolves.
  • Improve API to dump like json.dump and json.dumps.
    • Provide mypy plugin to check whether the class is encodable as JSON or not with @typedjson.encodable decorator.
  • Support type hints with forward reference.

Project details


Download files

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

Source Distribution

typedjson-0.7.1.tar.gz (4.6 kB view hashes)

Uploaded Source

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