dataclasses-json Counter deserialization example

Data.py

from collections import Counter
from dataclasses import dataclass, field

from dataclasses_json import dataclass_json

from utils import counter_config


@dataclass_json
@dataclass
class Data:
    count: Counter = field(default_factory=Counter, metadata=counter_config)


if __name__ == '__main__':
    d = Data()
    d.count["Fireball"] += 1
    d.count[42] = 13
    json = d.to_json()
    print(json)
    d2 = Data.from_json(json)
    print(d2)

utils.py

from collections import Counter
from typing import Any, Type

from dataclasses_json import config

separator = "://"
supported_types = [int, float]
encode_types: dict[Type, str] = {k: f"{k.__name__}{separator}" for k in supported_types}
decode_types: dict[str, Type] = {k.__name__: k for k in supported_types}


def counter_encoder(args: dict[Any, int]):
    return {f"{encode_types.get(type(k), k)}": v for k, v in args.items()}


def counter_decoder(args: dict[str, int]):
    ret: dict[Any, int] = {}
    for k, v in args.items():
        split = k.split(separator)
        ret[decode_types[split[0]](1) if split[0] in decode_types.keys() else k] = v

    return Counter(ret)


counter_config = config(encoder=counter_encoder, decoder=counter_decoder)