typedjson 0.3.0

JSON decoding for Python with type hinting (PEP 484)

typedjson

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

Requirements

• Python >= 3.7
• Use from __future__ import annotations (See PEP 563).
• Use non-generic or parameterized @dataclasses.dataclass without modifying __init__ to decode JSON as class.

Features

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

Example

from __future__ import annotations
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 path=('id',)>

Please refer to test codes for more detail.

TODO

• Use __init__.__annotation__ to decode JSON as arbitrary class.