113 lines
3.6 KiB
Python
113 lines
3.6 KiB
Python
"""
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Serialize data to/from JSON
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"""
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# Avoid shadowing the standard library json module
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from __future__ import absolute_import
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from __future__ import unicode_literals
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import datetime
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import decimal
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import json
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import sys
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from django.core.serializers.base import DeserializationError
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from django.core.serializers.python import Serializer as PythonSerializer
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from django.core.serializers.python import Deserializer as PythonDeserializer
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from django.utils import six
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from django.utils.timezone import is_aware
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class Serializer(PythonSerializer):
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"""
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Convert a queryset to JSON.
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"""
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internal_use_only = False
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def start_serialization(self):
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if json.__version__.split('.') >= ['2', '1', '3']:
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# Use JS strings to represent Python Decimal instances (ticket #16850)
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self.options.update({'use_decimal': False})
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self._current = None
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self.json_kwargs = self.options.copy()
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self.json_kwargs.pop('stream', None)
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self.json_kwargs.pop('fields', None)
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if self.options.get('indent'):
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# Prevent trailing spaces
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self.json_kwargs['separators'] = (',', ': ')
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self.stream.write("[")
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def end_serialization(self):
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if self.options.get("indent"):
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self.stream.write("\n")
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self.stream.write("]")
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if self.options.get("indent"):
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self.stream.write("\n")
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def end_object(self, obj):
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# self._current has the field data
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indent = self.options.get("indent")
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if not self.first:
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self.stream.write(",")
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if not indent:
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self.stream.write(" ")
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if indent:
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self.stream.write("\n")
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json.dump(self.get_dump_object(obj), self.stream,
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cls=DjangoJSONEncoder, **self.json_kwargs)
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self._current = None
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def getvalue(self):
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# Grand-parent super
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return super(PythonSerializer, self).getvalue()
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def Deserializer(stream_or_string, **options):
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"""
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Deserialize a stream or string of JSON data.
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"""
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if not isinstance(stream_or_string, (bytes, six.string_types)):
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stream_or_string = stream_or_string.read()
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if isinstance(stream_or_string, bytes):
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stream_or_string = stream_or_string.decode('utf-8')
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try:
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objects = json.loads(stream_or_string)
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for obj in PythonDeserializer(objects, **options):
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yield obj
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except GeneratorExit:
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raise
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except Exception as e:
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# Map to deserializer error
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six.reraise(DeserializationError, DeserializationError(e), sys.exc_info()[2])
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class DjangoJSONEncoder(json.JSONEncoder):
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"""
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JSONEncoder subclass that knows how to encode date/time and decimal types.
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"""
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def default(self, o):
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# See "Date Time String Format" in the ECMA-262 specification.
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if isinstance(o, datetime.datetime):
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r = o.isoformat()
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if o.microsecond:
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r = r[:23] + r[26:]
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if r.endswith('+00:00'):
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r = r[:-6] + 'Z'
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return r
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elif isinstance(o, datetime.date):
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return o.isoformat()
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elif isinstance(o, datetime.time):
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if is_aware(o):
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raise ValueError("JSON can't represent timezone-aware times.")
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r = o.isoformat()
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if o.microsecond:
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r = r[:12]
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return r
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elif isinstance(o, decimal.Decimal):
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return str(o)
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else:
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return super(DjangoJSONEncoder, self).default(o)
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# Older, deprecated class name (for backwards compatibility purposes).
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DateTimeAwareJSONEncoder = DjangoJSONEncoder
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