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Serialize data to/from JSON
import datetime
import decimal
import json
import uuid
from django.core.serializers.base import DeserializationError
from django.core.serializers.python import (
Deserializer as PythonDeserializer, Serializer as PythonSerializer,
from django.utils.duration import duration_iso_string
from django.utils.functional import Promise
from django.utils.timezone import is_aware
class Serializer(PythonSerializer):
"""Convert a queryset to JSON."""
internal_use_only = False
def _init_options(self):
self._current = None
self.json_kwargs = self.options.copy()
self.json_kwargs.pop('stream', None)
self.json_kwargs.pop('fields', None)
if self.options.get('indent'):
# Prevent trailing spaces
self.json_kwargs['separators'] = (',', ': ')
self.json_kwargs.setdefault('cls', DjangoJSONEncoder)
def start_serialization(self):
def end_serialization(self):
if self.options.get("indent"):"\n")"]")
if self.options.get("indent"):"\n")
def end_object(self, obj):
# self._current has the field data
indent = self.options.get("indent")
if not self.first:",")
if not indent:" ")
if indent:"\n")
json.dump(self.get_dump_object(obj),, **self.json_kwargs)
self._current = None
def getvalue(self):
# Grandparent super
return super(PythonSerializer, self).getvalue()
def Deserializer(stream_or_string, **options):
"""Deserialize a stream or string of JSON data."""
if not isinstance(stream_or_string, (bytes, str)):
stream_or_string =
if isinstance(stream_or_string, bytes):
stream_or_string = stream_or_string.decode()
objects = json.loads(stream_or_string)
yield from PythonDeserializer(objects, **options)
except (GeneratorExit, DeserializationError):
except Exception as exc:
raise DeserializationError() from exc
class DjangoJSONEncoder(json.JSONEncoder):
JSONEncoder subclass that knows how to encode date/time, decimal types, and
def default(self, o):
# See "Date Time String Format" in the ECMA-262 specification.
if isinstance(o, datetime.datetime):
r = o.isoformat()
if o.microsecond:
r = r[:23] + r[26:]
if r.endswith('+00:00'):
r = r[:-6] + 'Z'
return r
elif isinstance(o,
return o.isoformat()
elif isinstance(o, datetime.time):
if is_aware(o):
raise ValueError("JSON can't represent timezone-aware times.")
r = o.isoformat()
if o.microsecond:
r = r[:12]
return r
elif isinstance(o, datetime.timedelta):
return duration_iso_string(o)
elif isinstance(o, (decimal.Decimal, uuid.UUID, Promise)):
return str(o)
return super().default(o)