83 lines
2.5 KiB
Python
83 lines
2.5 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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import datetime
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import decimal
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import json
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from StringIO import StringIO
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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.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 end_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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json.dump(self.objects, self.stream, cls=DjangoJSONEncoder, **self.options)
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def getvalue(self):
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if callable(getattr(self.stream, 'getvalue', None)):
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return self.stream.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 isinstance(stream_or_string, basestring):
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stream = StringIO(stream_or_string)
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else:
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stream = stream_or_string
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try:
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for obj in PythonDeserializer(json.load(stream), **options):
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yield obj
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except GeneratorExit:
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raise
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except Exception, e:
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# Map to deserializer error
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raise DeserializationError(e)
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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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