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- """
- YAML serializer.
-
- Requires PyYaml (https://pyyaml.org/), but that's checked for in __init__.
- """
-
- import collections
- import decimal
- from io import StringIO
-
- import yaml
-
- from django.core.serializers.base import DeserializationError
- from django.core.serializers.python import (
- Deserializer as PythonDeserializer, Serializer as PythonSerializer,
- )
- from django.db import models
-
- # Use the C (faster) implementation if possible
- try:
- from yaml import CSafeLoader as SafeLoader
- from yaml import CSafeDumper as SafeDumper
- except ImportError:
- from yaml import SafeLoader, SafeDumper
-
-
- class DjangoSafeDumper(SafeDumper):
- def represent_decimal(self, data):
- return self.represent_scalar('tag:yaml.org,2002:str', str(data))
-
- def represent_ordered_dict(self, data):
- return self.represent_mapping('tag:yaml.org,2002:map', data.items())
-
-
- DjangoSafeDumper.add_representer(decimal.Decimal, DjangoSafeDumper.represent_decimal)
- DjangoSafeDumper.add_representer(collections.OrderedDict, DjangoSafeDumper.represent_ordered_dict)
-
-
- class Serializer(PythonSerializer):
- """Convert a queryset to YAML."""
-
- internal_use_only = False
-
- def handle_field(self, obj, field):
- # A nasty special case: base YAML doesn't support serialization of time
- # types (as opposed to dates or datetimes, which it does support). Since
- # we want to use the "safe" serializer for better interoperability, we
- # need to do something with those pesky times. Converting 'em to strings
- # isn't perfect, but it's better than a "!!python/time" type which would
- # halt deserialization under any other language.
- if isinstance(field, models.TimeField) and getattr(obj, field.name) is not None:
- self._current[field.name] = str(getattr(obj, field.name))
- else:
- super().handle_field(obj, field)
-
- def end_serialization(self):
- yaml.dump(self.objects, self.stream, Dumper=DjangoSafeDumper, **self.options)
-
- def getvalue(self):
- # Grandparent super
- return super(PythonSerializer, self).getvalue()
-
-
- def Deserializer(stream_or_string, **options):
- """Deserialize a stream or string of YAML data."""
- if isinstance(stream_or_string, bytes):
- stream_or_string = stream_or_string.decode()
- if isinstance(stream_or_string, str):
- stream = StringIO(stream_or_string)
- else:
- stream = stream_or_string
- try:
- yield from PythonDeserializer(yaml.load(stream, Loader=SafeLoader), **options)
- except (GeneratorExit, DeserializationError):
- raise
- except Exception as exc:
- raise DeserializationError() from exc
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