如何将django Model对象转换为包含所有字段的dict ?理想情况下,所有字段都包含外键和editable=False。
让我详细说明一下。假设我有一个django模型,如下所示:
from django.db import models
class OtherModel(models.Model): pass
class SomeModel(models.Model):
normal_value = models.IntegerField()
readonly_value = models.IntegerField(editable=False)
auto_now_add = models.DateTimeField(auto_now_add=True)
foreign_key = models.ForeignKey(OtherModel, related_name="ref1")
many_to_many = models.ManyToManyField(OtherModel, related_name="ref2")
在终端中,我做了以下工作:
other_model = OtherModel()
other_model.save()
instance = SomeModel()
instance.normal_value = 1
instance.readonly_value = 2
instance.foreign_key = other_model
instance.save()
instance.many_to_many.add(other_model)
instance.save()
我想把它转换成下面的字典:
{'auto_now_add': datetime.datetime(2015, 3, 16, 21, 34, 14, 926738, tzinfo=<UTC>),
'foreign_key': 1,
'id': 1,
'many_to_many': [1],
'normal_value': 1,
'readonly_value': 2}
回答不满意的问题:
Django:将整个Model对象集转换为单个字典
如何将Django Model对象转换为字典,同时还保留外键?
我创建了一个小片段,利用django的model_to_dict,但遍历对象的关系。
对于循环依赖项,它终止递归并放入引用依赖项对象的字符串。您可以将其扩展为包含不可编辑字段。
我在测试期间使用它来创建模型快照。
from itertools import chain
from django.db.models.fields.files import FileField, ImageField
from django.forms.models import model_to_dict
def get_instance_dict(instance, already_passed=frozenset()):
"""Creates a nested dict version of a django model instance
Follows relationships recursively, circular relationships are terminated by putting
a model identificator `{model_name}:{instance.id}`.
Ignores image and file fields."""
instance_dict = model_to_dict(
instance,
fields=[
f
for f in instance._meta.concrete_fields
if not isinstance(f, (ImageField, FileField))
],
)
already_passed = already_passed.union(
frozenset((f"{instance.__class__.__name__}:{instance.id}",))
)
# Go through possible relationships
for field in chain(instance._meta.related_objects, instance._meta.concrete_fields):
if (
(field.one_to_one or field.many_to_one)
and hasattr(instance, field.name)
and (relation := getattr(instance, field.name))
):
if (
model_id := f"{relation.__class__.__name__}:{relation.id}"
) in already_passed:
instance_dict[field.name] = model_id
else:
instance_dict[field.name] = get_instance_dict(relation, already_passed)
if field.one_to_many or field.many_to_many:
relations = []
for relation in getattr(instance, field.get_accessor_name()).all():
if (
model_id := f"{relation.__class__.__name__}:{relation.id}"
) in already_passed:
relations.append(model_id)
else:
relations.append(get_instance_dict(relation, already_passed))
instance_dict[field.get_accessor_name()] = relations
return instance_dict
(不是故意的)
好吧,它并不依赖于类型。我可能误解了最初的问题,所以如果是这样的话请原谅我。如果你创建serliazers.py,那么你在里面创建了有元类的类。
Class MyModelSerializer(serializers.ModelSerializer):
class Meta:
model = modelName
fields =('csv','of','fields')
然后,当你在视图类中获得数据时,你可以:
model_data - Model.objects.filter(...)
serializer = MyModelSerializer(model_data, many=True)
return Response({'data': serilaizer.data}, status=status.HTTP_200_OK)
这就是我在很多地方所拥有的,它通过JSONRenderer返回漂亮的JSON。
正如我所说,这是由DjangoRestFramework提供的,所以值得研究一下。
我创建了一个小片段,利用django的model_to_dict,但遍历对象的关系。
对于循环依赖项,它终止递归并放入引用依赖项对象的字符串。您可以将其扩展为包含不可编辑字段。
我在测试期间使用它来创建模型快照。
from itertools import chain
from django.db.models.fields.files import FileField, ImageField
from django.forms.models import model_to_dict
def get_instance_dict(instance, already_passed=frozenset()):
"""Creates a nested dict version of a django model instance
Follows relationships recursively, circular relationships are terminated by putting
a model identificator `{model_name}:{instance.id}`.
Ignores image and file fields."""
instance_dict = model_to_dict(
instance,
fields=[
f
for f in instance._meta.concrete_fields
if not isinstance(f, (ImageField, FileField))
],
)
already_passed = already_passed.union(
frozenset((f"{instance.__class__.__name__}:{instance.id}",))
)
# Go through possible relationships
for field in chain(instance._meta.related_objects, instance._meta.concrete_fields):
if (
(field.one_to_one or field.many_to_one)
and hasattr(instance, field.name)
and (relation := getattr(instance, field.name))
):
if (
model_id := f"{relation.__class__.__name__}:{relation.id}"
) in already_passed:
instance_dict[field.name] = model_id
else:
instance_dict[field.name] = get_instance_dict(relation, already_passed)
if field.one_to_many or field.many_to_many:
relations = []
for relation in getattr(instance, field.get_accessor_name()).all():
if (
model_id := f"{relation.__class__.__name__}:{relation.id}"
) in already_passed:
relations.append(model_id)
else:
relations.append(get_instance_dict(relation, already_passed))
instance_dict[field.get_accessor_name()] = relations
return instance_dict
只有vars(obj),它将声明对象的整个值
>>> obj_attrs = vars(obj)
>>> obj_attrs
{'_file_data_cache': <FileData: Data>,
'_state': <django.db.models.base.ModelState at 0x7f5c6733bad0>,
'aggregator_id': 24,
'amount': 5.0,
'biller_id': 23,
'datetime': datetime.datetime(2018, 1, 31, 18, 43, 58, 933277, tzinfo=<UTC>),
'file_data_id': 797719,
}
你也可以加上这个
>>> keys = obj_attrs.keys()
>>> temp = [obj_attrs.pop(key) if key.startswith('_') else None for key in keys]
>>> del temp
>>> obj_attrs
{
'aggregator_id': 24,
'amount': 5.0,
'biller_id': 23,
'datetime': datetime.datetime(2018, 1, 31, 18, 43, 58, 933277, tzinfo=<UTC>),
'file_data_id': 797719,
}