Better json.dumps supporting set, datetime, timedelta, decimal, object, and sqlalchemy objects

better_dumps.py

__all__ = ["better_dumps", "better_dump", "json_debug"]

import dataclasses
import datetime
import decimal
import json
from inspect import ismethod

import jsonpickle
from loguru import logger
from sqlalchemy.ext.declarative import DeclarativeMeta


class BasicJSONEncoder(json.JSONEncoder):
    def default(_, o):
        if isinstance(o, (datetime.datetime, datetime.date, datetime.time)):
            return o.isoformat()
        if isinstance(o, datetime.timedelta):
            return (datetime.datetime.min + o).time().isoformat()
        if dataclasses.is_dataclass(o):
            return dataclasses.asdict(o)
        if isinstance(o, decimal.Decimal):
            return float(o)
        if isinstance(o, bytes):
            try:
                return o.decode()
            except:
                return "failed-to-encode(1)"
        if isinstance(o, set):
            return list(o)
        if isinstance(o, object):
            return o.__dict__
        return super().default(o)


class BetterJSONEncoder(json.JSONEncoder):
    def default(_, o):
        if isinstance(o.__class__, DeclarativeMeta):
            # an SQLAlchemy class
            fields = {}
            for field in [
                x for x in dir(o) if not x.startswith("_") and x != "metadata"
            ]:
                data = o.__getattribute__(field)
                if not ismethod(data):
                    try:
                        json.dumps(data, cls=BasicJSONEncoder)
                        fields[field] = data
                    except (TypeError, AttributeError) as e:
                        logger.debug(e)
                        fields[field] = "failed-to-encode(2)"
            return fields
        if isinstance(o, (datetime.datetime, datetime.date, datetime.time)):
            return o.isoformat()
        if isinstance(o, datetime.timedelta):
            return (datetime.datetime.min + o).time().isoformat()
        if dataclasses.is_dataclass(o):
            return dataclasses.asdict(o)
        if isinstance(o, decimal.Decimal):
            return float(o)
        if isinstance(o, bytes):
            try:
                return o.decode()
            except:
                return "failed-to-encode(1)"
        if isinstance(o, set):
            return list(o)
        if isinstance(o, object):
            return o.__dict__
        return super().default(o)


def better_dumps(obj, doprint=True, indent=True):
    if indent:
        s = json.dumps(obj, cls=BetterJSONEncoder, indent=indent)
    else:
        s = json.dumps(obj, cls=BetterJSONEncoder)
    if doprint:
        print(s)
    else:
        return s


def simplify_object(obj):
    s = json.dumps(obj, cls=BetterJSONEncoder)
    return json.loads(s)


def better_dump(obj, file_location: str):
    with open(file_location, "w") as outfile:
        json.dump(obj, outfile, cls=BetterJSONEncoder, indent=2)


def json_debug(obj):
    """
    use this only as last resort. when BetterJSONEncoder fails
    """
    data = json.dumps(json.loads(str(jsonpickle.encode(obj))), indent=2, sort_keys=True)
    print(data)


def sqlalchemy_to_dict(result_proxy):
    """
    Convert the result of fetch(), fetchall() into dict from result proxy
    """
    return [
        {column: value for column, value in rowproxy.items()}
        for rowproxy in result_proxy
    ]

Usage:

# as string
better_dumps(some_object, doprint=False)

# debug an object
better_dumps(some_object)

# to file
better_dump(some_object)

# turn complicated object to simpler project, by encoding/decoding as JSON
simplify_object(some_object)