Python Django Rest框架中*************处的断言错误

我正在Django rest框架中开发ModelSerializer

型号.py

from __future__ import unicode_literals
from django.db import models
from django.contrib.postgres.fields import ArrayField
from django.contrib.postgres.fields import HStoreField
from django.contrib.postgres.validators import KeysValidator

    class Component(models.Model):
        component_name = models.CharField(max_length=50)
        allowed_extensions = ArrayField(models.CharField(max_length=50))

        def __str__(self):
            return self.component_name

    class Image_Type(models.Model):
        image_name = models.CharField(max_length=30)
        def __str__(self):
            return self.image_name
    class Image_Component(models.Model):
        component_name = models.ForeignKey('Component')
        image_name = models.ForeignKey('Image_Type')
    class Image_Meta(models.Model):
        image_component = models.ForeignKey('Image_Component',on_delete=models.CASCADE,)
        component_id = models.IntegerField()
        image_count = models.IntegerField(default=0)
        version = models.CharField(max_length=10)

    class Image(models.Model):
        image_meta = models.ForeignKey('Image_Meta',on_delete=models.CASCADE,)
        image_path = models.URLField(max_length=200)
        order = models.IntegerField()
        version = models.CharField(max_length=10)


    class Feature(models.Model):
        image_component = models.ForeignKey('Image_Component',on_delete=models.CASCADE,)
        feature_value = HStoreField()
        def save(self,*args,**kwargs):
            if Feature.objects.filter(feature_value__has_keys=['size', 'quality' , 'format']):
                super(Feature, self).save(*args, **kwargs)
            else:
                print("Incorrect key entered")

from rest_framework import serializers
from models import Component , Image_Type , Image_Component , Image , Feature , Image_Meta
from django.contrib.postgres.fields import ArrayField
from django.contrib.postgres.fields import HStoreField


class ComponentSerializer(serializers.ModelSerializer):
    class Meta:
        model = Component
        field = {'component_name','allowed_extensions'}


class Image_TypeSerializer(serializers.ModelSerializer):
    class Meta:
        model = Image_Type
        field = {'image_name'}



class Image_ComponentSerializer(serializers.ModelSerializer):
    component_name = ComponentSerializer()
    image_name = Image_TypeSerializer()
    class Meta:
        model = Image_Component
        field = {'component_name','image_name'}

    def create(self, validated_data):
        component_data = validated_data.pop('component_name')
        image_data = validated_data.pop('image_name')
        image_component = Image_Component.objects.create(**validated_data)

        for component_data in component_data:
            Component.objects.create(image_component=image_component, **component_data)

        for image_data in image_data:
            Image_Type.objects.create(image_component=image_component, **image_data)

        return image_component

class Image_MetaSerializer(serializers.ModelSerializer):
    image_component = Image_ComponentSerializer()
    class Meta:
        model = Image_Meta
        field = {'image_component','component_id' , 'image_count', 'version'}

class ImageSerializer(serializers.ModelSerializer):
    image_meta = Image_MetaSerializer()
    class Meta:
        model = Image_Meta
        field = {'image_meta' , 'image_path' , 'order' , 'version'}

class FeatureSerializer(serializers.ModelSerializer):
    image_component = Image_ComponentSerializer()
    class Meta:
        model = Feature
        field = {'image_component' , 'feature_value'}

from django.conf.urls import patterns , include , url
from rest_framework.urlpatterns import format_suffix_patterns
from imagedata import views

urlpatterns = patterns('',
    url(r'^api/component$',views.Component.as_view()),
    url(r'^api/image_type$',views.Image_Type.as_view()),
    url(r'^api/image_meta$',views.Image_Meta.as_view()),
    url(r'^api/image_component$',views.Image_Component.as_view()),
    url(r'^api/image$',views.Image.as_view()),
    url(r'^api/feature$',views.Feature.as_view()),
)

urlpatterns = format_suffix_patterns(urlpatterns)

序列化程序.py

from __future__ import unicode_literals
from django.db import models
from django.contrib.postgres.fields import ArrayField
from django.contrib.postgres.fields import HStoreField
from django.contrib.postgres.validators import KeysValidator

    class Component(models.Model):
        component_name = models.CharField(max_length=50)
        allowed_extensions = ArrayField(models.CharField(max_length=50))

        def __str__(self):
            return self.component_name

    class Image_Type(models.Model):
        image_name = models.CharField(max_length=30)
        def __str__(self):
            return self.image_name
    class Image_Component(models.Model):
        component_name = models.ForeignKey('Component')
        image_name = models.ForeignKey('Image_Type')
    class Image_Meta(models.Model):
        image_component = models.ForeignKey('Image_Component',on_delete=models.CASCADE,)
        component_id = models.IntegerField()
        image_count = models.IntegerField(default=0)
        version = models.CharField(max_length=10)

    class Image(models.Model):
        image_meta = models.ForeignKey('Image_Meta',on_delete=models.CASCADE,)
        image_path = models.URLField(max_length=200)
        order = models.IntegerField()
        version = models.CharField(max_length=10)


    class Feature(models.Model):
        image_component = models.ForeignKey('Image_Component',on_delete=models.CASCADE,)
        feature_value = HStoreField()
        def save(self,*args,**kwargs):
            if Feature.objects.filter(feature_value__has_keys=['size', 'quality' , 'format']):
                super(Feature, self).save(*args, **kwargs)
            else:
                print("Incorrect key entered")

from rest_framework import serializers
from models import Component , Image_Type , Image_Component , Image , Feature , Image_Meta
from django.contrib.postgres.fields import ArrayField
from django.contrib.postgres.fields import HStoreField


class ComponentSerializer(serializers.ModelSerializer):
    class Meta:
        model = Component
        field = {'component_name','allowed_extensions'}


class Image_TypeSerializer(serializers.ModelSerializer):
    class Meta:
        model = Image_Type
        field = {'image_name'}



class Image_ComponentSerializer(serializers.ModelSerializer):
    component_name = ComponentSerializer()
    image_name = Image_TypeSerializer()
    class Meta:
        model = Image_Component
        field = {'component_name','image_name'}

    def create(self, validated_data):
        component_data = validated_data.pop('component_name')
        image_data = validated_data.pop('image_name')
        image_component = Image_Component.objects.create(**validated_data)

        for component_data in component_data:
            Component.objects.create(image_component=image_component, **component_data)

        for image_data in image_data:
            Image_Type.objects.create(image_component=image_component, **image_data)

        return image_component

class Image_MetaSerializer(serializers.ModelSerializer):
    image_component = Image_ComponentSerializer()
    class Meta:
        model = Image_Meta
        field = {'image_component','component_id' , 'image_count', 'version'}

class ImageSerializer(serializers.ModelSerializer):
    image_meta = Image_MetaSerializer()
    class Meta:
        model = Image_Meta
        field = {'image_meta' , 'image_path' , 'order' , 'version'}

class FeatureSerializer(serializers.ModelSerializer):
    image_component = Image_ComponentSerializer()
    class Meta:
        model = Feature
        field = {'image_component' , 'feature_value'}

from django.conf.urls import patterns , include , url
from rest_framework.urlpatterns import format_suffix_patterns
from imagedata import views

urlpatterns = patterns('',
    url(r'^api/component$',views.Component.as_view()),
    url(r'^api/image_type$',views.Image_Type.as_view()),
    url(r'^api/image_meta$',views.Image_Meta.as_view()),
    url(r'^api/image_component$',views.Image_Component.as_view()),
    url(r'^api/image$',views.Image.as_view()),
    url(r'^api/feature$',views.Feature.as_view()),
)

urlpatterns = format_suffix_patterns(urlpatterns)

url.py

from __future__ import unicode_literals
from django.db import models
from django.contrib.postgres.fields import ArrayField
from django.contrib.postgres.fields import HStoreField
from django.contrib.postgres.validators import KeysValidator

    class Component(models.Model):
        component_name = models.CharField(max_length=50)
        allowed_extensions = ArrayField(models.CharField(max_length=50))

        def __str__(self):
            return self.component_name

    class Image_Type(models.Model):
        image_name = models.CharField(max_length=30)
        def __str__(self):
            return self.image_name
    class Image_Component(models.Model):
        component_name = models.ForeignKey('Component')
        image_name = models.ForeignKey('Image_Type')
    class Image_Meta(models.Model):
        image_component = models.ForeignKey('Image_Component',on_delete=models.CASCADE,)
        component_id = models.IntegerField()
        image_count = models.IntegerField(default=0)
        version = models.CharField(max_length=10)

    class Image(models.Model):
        image_meta = models.ForeignKey('Image_Meta',on_delete=models.CASCADE,)
        image_path = models.URLField(max_length=200)
        order = models.IntegerField()
        version = models.CharField(max_length=10)


    class Feature(models.Model):
        image_component = models.ForeignKey('Image_Component',on_delete=models.CASCADE,)
        feature_value = HStoreField()
        def save(self,*args,**kwargs):
            if Feature.objects.filter(feature_value__has_keys=['size', 'quality' , 'format']):
                super(Feature, self).save(*args, **kwargs)
            else:
                print("Incorrect key entered")

from rest_framework import serializers
from models import Component , Image_Type , Image_Component , Image , Feature , Image_Meta
from django.contrib.postgres.fields import ArrayField
from django.contrib.postgres.fields import HStoreField


class ComponentSerializer(serializers.ModelSerializer):
    class Meta:
        model = Component
        field = {'component_name','allowed_extensions'}


class Image_TypeSerializer(serializers.ModelSerializer):
    class Meta:
        model = Image_Type
        field = {'image_name'}



class Image_ComponentSerializer(serializers.ModelSerializer):
    component_name = ComponentSerializer()
    image_name = Image_TypeSerializer()
    class Meta:
        model = Image_Component
        field = {'component_name','image_name'}

    def create(self, validated_data):
        component_data = validated_data.pop('component_name')
        image_data = validated_data.pop('image_name')
        image_component = Image_Component.objects.create(**validated_data)

        for component_data in component_data:
            Component.objects.create(image_component=image_component, **component_data)

        for image_data in image_data:
            Image_Type.objects.create(image_component=image_component, **image_data)

        return image_component

class Image_MetaSerializer(serializers.ModelSerializer):
    image_component = Image_ComponentSerializer()
    class Meta:
        model = Image_Meta
        field = {'image_component','component_id' , 'image_count', 'version'}

class ImageSerializer(serializers.ModelSerializer):
    image_meta = Image_MetaSerializer()
    class Meta:
        model = Image_Meta
        field = {'image_meta' , 'image_path' , 'order' , 'version'}

class FeatureSerializer(serializers.ModelSerializer):
    image_component = Image_ComponentSerializer()
    class Meta:
        model = Feature
        field = {'image_component' , 'feature_value'}

from django.conf.urls import patterns , include , url
from rest_framework.urlpatterns import format_suffix_patterns
from imagedata import views

urlpatterns = patterns('',
    url(r'^api/component$',views.Component.as_view()),
    url(r'^api/image_type$',views.Image_Type.as_view()),
    url(r'^api/image_meta$',views.Image_Meta.as_view()),
    url(r'^api/image_component$',views.Image_Component.as_view()),
    url(r'^api/image$',views.Image.as_view()),
    url(r'^api/feature$',views.Feature.as_view()),
)

urlpatterns = format_suffix_patterns(urlpatterns)

它适用于组件和图像类型模型，也就是说，如果我尝试更新这些表，我可以同时对这两种模型进行更新。但是对于image\u component模型，每当我尝试更新表时，我都会得到错误：

AssertionError at /imagedata/api/image_component
The `.create()` method does not support writable nestedfields by default.
Write an explicit `.create()` method for serializer `imagedata.serializers.Image_ComponentSerializer`, or set `read_only=True` on nested serializer fields.
Request Method: POST
Request URL:    http://127.0.0.1:8000/imagedata/api/image_component
Django Version: 1.9
Exception Type: AssertionError
Exception Value:    
The `.create()` method does not support writable nestedfields by default.
Write an explicit `.create()` method for serializer `imagedata.serializers.Image_ComponentSerializer`, or set `read_only=True` on nested serializer fields.
Exception Location: /Library/Python/2.7/site-packages/rest_framework/serializers.py in raise_errors_on_nested_writes, line 724
Python Executable:  /usr/bin/python
Python Version: 2.7.10

上的页面如下所示：

我可能完全错了，但我认为文本字段应该要求从组件和图像类型表中分别存在的组件名称和图像类型的值集中进行选择，但它们不是。我做错了什么？如何纠正这一点

---

Django管理员也没有问题。它工作得很好。

首先，我想说的是，我非常确定您遇到的错误是在

Image\u ComponentSerializer

上添加.create方法之前

由于

Image\u组件

基于两个外键，如果您希望在API中选择包含这两个外键的字段，只需将序列化程序更改为此（删除。创建方法，因为不需要）：

因此没有自定义序列化程序，但是这将影响

Image\u组件

对象的表示，它将显示FK字段的ID。要更改此行为，我将.

重写为\u表示法

方法，如下所示：

def to_representation(self, obj):  
    ret = {'component_name': ComponentSerializer(instance=obj.component_name).data,
           'image_name': ImageTypeSerializer(instance=obj.image_name).data}
    return ret

---

因此，输入将是FK的ID，输出将基于每个字段的自定义序列化程序。

我陷入了另一个问题。.问题在于feature table中feature_value字段中使用的Hstore字段。尝试在Django Rest Framework页面中保存功能值时，存储的功能值为空。你能帮我想个办法吗？