day72做业

day72做业
"""
一、新建一个django项目，定义一个Car类，有name字符串属性，color整型选择属性(0:银色，1:黑色，2:红色，3:灰色)，price全精度小数类型，image图片文件类型，brand字符串类型

二、基于ModelSerializer类，完成Car资源的单查，群查，单增接口
序列化：显示车名，车的颜色，车的价格，车的海报，车的品牌
反序列化：必须提供车名，车的价格，车的品牌(车的匹配须要二次确认re_brand)，车的颜色默认为银色(能够提供)，车的海报不须要提供(默认为空)
"""

models.py

class Car(models.Model):
name = models.CharField(max_length=64)
COLOR_CHOICES = (
(0, '银色'),
(1, '黑色'),
(2, '白色'),
(3, '红色'),
)
color = models.IntegerField(choices=COLOR_CHOICES, default=0)
price = models.DecimalField(max_digits=8, decimal_places=2)
img = models.ImageField(upload_to='img/', default='img/default.jpg')
brand = models.CharField(max_length=64)

# 自定义序列化字段
@property
def car_color(self):
    return self.get_color_display()

serializers.py

class CarModelSerializer(serializers.ModelSerializer):
# 自定义反序列化字段
re_price = serializers.DecimalField(max_digits=8, decimal_places=2, write_only=True)

class Meta:
    # 绑定类
    model = models.Car
    # 参与序列化与反序列化的字段
    fields = ['name', 'car_color', 'price', 'img', 'brand', 'color', 're_price']
    extra_kwargs = {
        'img': {
            'read_only': True
        },
        'color': {
            'write_only': True
        }
    }

# 全局钩子
def validate(self, attrs):
    price = attrs.get('price')
    re_price = attrs.pop('re_price')
    if not price == re_price:
        raise serializers.ValidationError({'re_price': '价格不一致!'})
    return attrs

views.py

class CarAPIView(APIView):
def get(self, request, *args, **kwargs):
pk = kwargs.get('pk')
# 单查
if pk:
car_obj = models.Car.objects.filter(pk=pk).first()
if not car_obj:
return Response({
'status': 1,
'msg': 'pk error'
}, status=400)
serializer_obj = serializers.CarModelSerializer(car_obj)

return Response({
            'status': 0,
            'msg': 'ok',
            'results': serializer_obj.data
        })
    # 群查
    car_query = models.Car.objects.all()
    serializer_obj = serializers.CarModelSerializer(car_query, many=True)
    return Response({
        'status': 0,
        'msg': 'ok',
        'results': serializer_obj.data
    })

def post(self, request, *args, **kwargs):
    # 单增
    serializer_obj = serializers.CarModelSerializer(data=request.data)
    # 校验不经过会自动将错误信息返回给前端
    serializer_obj.is_valid(raise_exception=True)
    car_obj = serializer_obj.save()

    return Response({
        'status': 0,
        'msg': 'ok',
        'results': serializers.CarModelSerializer(car_obj).data
    })