utils.py

import base64
import datetime
import decimal
import json
import pickle
import time


def _encode_pickle(data):
    """
    :returns: bytes -- encoded data
    """
    return base64.b64encode(
        # to be compatible with Python2
        pickle.dumps(data, protocol=2)
    )


def _decode_pickle(data):
    """
    :type data: bytes.
    """
    return pickle.loads(
        base64.b64decode(data)
    )


class JSONEncoder(json.JSONEncoder):
    def default(self, o):
        if isinstance(o, decimal.Decimal):
            return {'_serialized.decimal': str(o)}
        if isinstance(o, datetime.datetime):
            # doesn't preserve timezone
            return {'_serialized.datetime': o.timestamp()}
        if isinstance(o, datetime.date):
            return {'_serialized.date': int(time.mktime(o.timetuple()))}
        if isinstance(o, datetime.timedelta):
            return {'_serialized.timedelta': o.total_seconds()}
        return super().default(o)


class JSONDecoder(json.JSONDecoder):
    def decode(self, s, **kwargs):
        obj = super().decode(s, **kwargs)
        if not isinstance(obj, dict):
            return obj
        if '_serialized.decimal' in obj:
            return decimal.Decimal(obj['_serialized.decimal'])
        if '_serialized.datetime' in obj:
            return datetime.datetime.fromtimestamp(obj['_serialized.datetime'])
        if '_serialized.date' in obj:
             return datetime.date.fromtimestamp(obj['_serialized.date'])
        if '_serialized.timedelta' in obj:
            return datetime.timedelta(seconds=obj['_serialized.timedelta'])
        return obj


json_encoder = JSONEncoder()
json_decoder = JSONDecoder()


def _encode_json(data):
    return json_encoder.encode(data).encode()


def _decode_json(data):
    return json_decoder.decode(data.decode())

encode = _encode_json
decode = _decode_json