0.介绍

a. 本文介绍了常用的，视图&反序列化&序列化，中使用的方法。

b. 序列化器他有两个作用：序列化、校验。

c. 序列化、校验，可以走一个序列化器，也可以走两个。

1. 视图

1.1 选择serializer

class TestView(ListAPIView,CreateAPIView):queryset = models.Topic.objectsserializer_class = TestSERdef get_serializer_class(self):# self.auction == 'list'if self.request.method == "GET":return TestSERreturn TestSER2

1.2 选择authenticator

权限频率都是一样的使用，都是做判断，返回一个对象列表即可

class CommentAPIView(APIView):"""获取更多评论"""def get_authenticators(self):# 重写认证类if self.request.method == 'POST':return [LoginAuthentication(), ]return [PublicAuthentication(), ]def get(self, request, *args, **kwargs):"""获取更多评论，通过root"""# print('1', request.user)root = int(request.query_params.get('root'))# print(root)queryset = models.Comment.objects.filter(root=root)# print(queryset)ser = CommentModelSerializer(instance=queryset, many=True)return Response(data=ser.data)def post(self, request, *args, **kwargs):"""保存评论数据"""ser = PostCommentModelSerializer(data=request.data)  # ...# print(request.data)if ser.is_valid():ser.save(userinfo_id=request.user)# 评论数+1new_id = ser.validated_data.get('new').idmodels.Release.objects.filter(id=new_id).update(release_num=F('release_num') + 1)return Response(ser.data, status=status.HTTP_201_CREATED)return Response(ser.errors, status=status.HTTP_400_BAD_REQUEST)

1.3 自定义视图函数

比如：继承ListAPIView重写list方法,

继承RetrieveAPIView重写list方法retrieve

class AuctionItemDetailView(RetrieveAPIView):"""拍品详细,前端传过来，相应的商品id"""queryset = models.AuctionItem.objects.filter(status__gt=1)serializer_class = AuctionItemDetailModelSerializerdef retrieve(self, request, *args, **kwargs):response = super(AuctionItemDetailView, self).retrieve(request, *args, **kwargs)# 路由的pk可以从kwargs中取pk = kwargs.get('pk')user_obj = request.userif user_obj:models.BrowseRecord.objects.get_or_create(user=user_obj, item_id=pk)# 商品记录加一models.AuctionItem.objects.filter(pk=pk).update(look_count=F('look_count') + 1)return response

1.4 自定义filter做筛选

自定义过滤/分页，实现微信小程序，上拉下拉https://blog.csdn.net/qq_52385631/article/details/123101613?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522164623539316780265457863%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fblog.%2522%257D&request_id=164623539316780265457863&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2~blog~first_rank_ecpm_v1~rank_v31_ecpm-15-123101613.nonecase&utm_term=%E5%BE%AE%E4%BF%A1&spm=1018.2226.3001.4450

1.5 perform_create(用户自己传入一些数据)

# 用户自己传入一些数据
# 与重写create不同的是，perform_create，使用默认的create，但可以自己传入数据# 案例class CommentAPIView(ListAPIView, CreateAPIView):"""获取更多评论&&保存评论视图"""queryset = models.Comment.objects.all()serializer_class = TextSerializerdef perform_create(self, serializer):# 执行创建传入默认的数据serializer.save(userinfo=self.request.user)

1.5 重写视图/添加过滤条件/create之前

class AuctionBidView(ListAPIView, CreateAPIView):"""竞价 www.xxxx.com/../../?item_id=1"""authentication_classes = [LoginAuthentication, ]queryset = models.BidRecord.objects.filter(status=1)serializer_class = BidRecordModelSerializerdef get_queryset(self):# 进行过滤，找到当前出价的商品item_id = self.request.query_params.get('item_id')queryset = self.queryset.filter(item_id=item_id)return querysetdef get(self, request, *args, **kwargs):# 重写get，构造返回的数据response = super(AuctionBidView, self).get(request, *args, **kwargs)# 序列化之后的数据# [OrderedDict([('id', 1), ('status', '竞价'), ('item', 2), ('user', 1)]), OrderedDict([('id', 2), ('status', '竞价'), ('item', 2), ('user', 1)])]# print(response.data)item_id = self.request.query_params.get('item_id')item_obj = models.AuctionItem.objects.filter(id=item_id).first()# 取最大价格，如果没有，取低价# 进行聚合，求出最大值，{'max_price':1200}max_price = models.BidRecord.objects.filter(status=1, item_id=item_id).aggregate(max_price=Max('price'))['max_price']data = {'unit': item_obj.unit,'price': max_price or item_obj.start_price,'result': response.data}response.data = datareturn responsedef perform_create(self, serializer):# 用户自己添加数据# 添加锁from django.db import transactionfrom rest_framework.exceptions import ValidationErrorwith transaction.atomic():item_id = self.request.data.get('item_id')price = self.request.data.get('price')# 加锁，同一个价格只能一个出价  select_for_updateresult = models.BidRecord.objects.filter(status=1, item_id=item_id).aggregate(max_price=Max('price')).select_for_update()max_price = result.get('max_price')if price < max_price:raise ValidationError('价格不够！')serializer.save(user=self.request.user)

1.6 重写视图，拿到序列化好的字段，进行修改

1.6.1 案例一

    def get(self, request, *args, **kwargs):# 重写get，构造返回的数据response = super(AuctionBidView, self).get(request, *args, **kwargs)# 序列化之后的数据# [OrderedDict([('id', 1), ('status', '竞价'), ('item', 2), ('user', 1)]), OrderedDict([('id', 2), ('status', '竞价'), ('item', 2), ('user', 1)])]# print(response.data)item_id = self.request.query_params.get('item_id')item_obj = models.AuctionItem.objects.filter(id=item_id).first()# 取最大价格，如果没有，取低价# 进行聚合，求出最大值，{'max_price':1200}max_price = models.BidRecord.objects.filter(status=1, item_id=item_id).aggregate(max_price=Max('price'))['max_price']data = {'unit': item_obj.unit,'price': max_price or item_obj.start_price,'result': response.data}response.data = datareturn response

1.6.2 案例二

class CouponUserView(ListAPIView, CreateAPIView):"""用户的优惠劵"""authentication_classes = [LoginAuthentication, ]serializer_class = CouponUserSerializerdef get_queryset(self):queryset = models.UserCoupon.objects.filter(user=self.request.user, is_delete=False, is_show=True).order_by('-id')return querysetdef list(self, request, *args, **kwargs):response = super(CouponUserView, self).list(request, *args, **kwargs)# 如果有问题，报错if response.status_code != status.HTTP_200_OK:return response# 更改返回的格式 {1：{'text':'未使用',child:[] }}# 有序字典status_dict = OrderedDict()for item in models.UserCoupon.status_type:status_dict[item[0]] = {'text': item[1], 'child': []}for row in response.data:# print(row)status_dict[int(row['status'])]['child'].append(row)response.data = status_dictreturn response

2. 反序列化

2.1 普通校验

class TestSER(serializers.ModelSerializer):class Meta:model = models.Topicfields = "__all__"

2.2 自定义校验规则---validators

import re
from rest_framework.exceptions import ValidationErrordef phone_validator(value):if not re.match(r"^(1[3|4|5|6|7|8|9])\d{9}$",value):raise ValidationError('手机格式错误')class TestSER(serializers.ModelSerializer):title = serializers.CharField(label='手机号',validators=[phone_validator,])class Meta:model = models.Topicfields = "__all__"

2.3 自定义方法校验---全局/局部钩子

class TestSER(serializers.ModelSerializer):title = serializers.CharField(label='手机号')class Meta:model = models.Topicfields = "__all__"def validate_title(self, value):# 具体的校验规则return value

2.4 序列化嵌套(反序列化) 一般前端传送列表套字典，都是用该方法

url path('release/', ReleaseAPIView.as_view()),view
from rest_framework.views import APIView
from utils.centent.cos import credential
from rest_framework.response import Response
from rest_framework.generics import CreateAPIViewfrom api.serializer import businessclass ReleaseAPIView(CreateAPIView):"""发布保存视图"""serializer_class = business.ReleaseModelSerializerdef get_queryset(self):# 重写querysetqueryset = models.Release.objects.filter(is_delete=False, is_show=True)return querysetdef post(self, request, *args, **kwargs):# 重写postresponse = super(ReleaseAPIView, self).post(request, *args, **kwargs)# 进行自定义返回数据response.data = ''return responsedef perform_create(self, serializer):"""在保存之前为对应的topic人数+1"""print("serializer", serializer.data)# serializer {'position': 'xx', 'content': 'xx', 'userinfo': 2, 'topic': 1, 'imageList': [OrderedDict([('cos_url', 'xx'), ('cos_media_name', 'xx')]), OrderedDict([('cos_url', 'xx'), ('cos_media_name', 'xx')])]}print("serializer", serializer.data.get('topic'))# serializer 1serfrom rest_framework import serializersfrom api import modelsclass MediaModelSerializer(serializers.ModelSerializer):# 用作序列化器嵌套class Meta:model = models.Mediafields = ['cos_url', 'cos_media_name']class ReleaseModelSerializer(serializers.ModelSerializer):"""发布保存序列化器"""# imageList默认会序列化，必须加一个write_only，不然报错imageList = MediaModelSerializer(many=True, write_only=True)class Meta:model = models.Releasefields = ['position', 'content', 'userinfo', 'topic', 'imageList']def validate(self, attrs):imageList = attrs.get('imageList')# print(imageList)  # [OrderedDict([('cos_url', 'xx'), ('cos_media_name', 'xx')]), OrderedDict([('cos_url', 'xx'), ('cos_media_name', 'xx')])]return attrs

2.5 某个字段，反序列化不进行校验，序列化的时候忽略

class TestSER(serializers.ModelSerializer):# 序列化忽略name = serializers.CharField(label='手机号',wirte_only=True)# 反序列化不进行校验title = serializers.CharField(label='手机号',read_only=True)class Meta:model = models.Topicfields = "__all__"

2.6 ps 关于write_only/read_only 详解

详解https://blog.csdn.net/qq_52385631/article/details/122767023?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522164604096016780366595849%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fblog.%2522%257D&request_id=164604096016780366595849&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2~blog~first_rank_ecpm_v1~rank_v31_ecpm-3-122767023.nonecase&utm_term=%E5%BA%8F%E5%88%97%E5%8C%96&spm=1018.2226.3001.4450

3. 序列化

3.1 普通序列化

class TestSER(serializers.ModelSerializer):class Meta:model = models.Topicfields = "__all__"

3.2 自定义字段+source

class TestSER(serializers.ModelSerializer):v1 = serializers.CharField(label='手机号',source='get_gender_display')class Meta:model = models.Topicfields = "__all__"

3.3 自定义时间字段

class TestSER(serializers.ModelSerializer):v1 = serializers.DateTimeField(format="%Y")class Meta:model = models.Topicfields = "__all__"

3.4 自定义返回格式---get_xxx

from django.forms.models import model_to_dictclass NewsDetailModelSerializer(serializers.ModelSerializer):images = serializers.SerializerMethodField()create_date = serializers.DateTimeField(format="%Y-%m-%d %H:%M")user = serializers.SerializerMethodField()topic = serializers.SerializerMethodField()viewer = serializers.SerializerMethodField()comment = serializers.SerializerMethodField()is_favor = serializers.SerializerMethodField()class Meta:model = models.Newsexclude = ['cover',]def get_images(self,obj):detail_queryset = models.NewsDetail.objects.filter(news=obj)# return [row.cos_path for row in detail_queryset]# return [{'id':row.id,'path':row.cos_path} for row in detail_queryset]return [model_to_dict(row,['id','cos_path']) for row in detail_queryset]def get_user(self, obj):return model_to_dict(obj.user, fields=['id', 'nickname', 'avatar'])def get_topic(self, obj):if not obj.topic:returnreturn model_to_dict(obj.topic, fields=['id', 'title'])def get_viewer(self,obj):# 根据新闻的对象 obj(news)# viewer_queryset = models.ViewerRecord.objects.filter(news_id=obj.id).order_by('-id')[0:10]queryset = models.ViewerRecord.objects.filter(news_id=obj.id)viewer_object_list = queryset.order_by('-id')[0:10]context = {'count':queryset.count(),'result': [model_to_dict(row.user,['nickname','avatar']) for row in viewer_object_list]}return contextdef get_comment(self,obj):"""获取所有的1级评论，再给每个1级评论获取一个耳机评论。:param obj::return:"""# 1.获取所有的 一级 评论first_queryset = models.CommentRecord.objects.filter(news=obj,depth=1).order_by('id')[0:10].values('id','content','depth','user__nickname','user__avatar','create_date')first_id_list = [ item['id'] for item in first_queryset]# 2.获取所有的二级评论# second_queryset = models.CommentRecord.objects.filter(news=obj,depth=2)# 2. 获取所有1级评论下的二级评论# second_queryset = models.CommentRecord.objects.filter(news=obj, depth=2,reply_id__in=first_id_list)# 2. 获取所有1级评论下的二级评论(每个二级评论只取最新的一条)from django.db.models import Maxresult = models.CommentRecord.objects.filter(news=obj, depth=2, reply_id__in=first_id_list).values('reply_id').annotate(max_id=Max('id'))second_id_list = [item['max_id'] for item in result] # 5, 8second_queryset = models.CommentRecord.objects.filter(id__in=second_id_list).values('id','content','depth','user__nickname','user__avatar','create_date','reply_id','reply__user__nickname')import collectionsfirst_dict = collections.OrderedDict()for item in first_queryset:item['create_date'] = item['create_date'].strftime('%Y-%m-%d')first_dict[item['id']] = itemfor node in second_queryset:first_dict[node['reply_id']]['child'] = [node,]return first_dict.values()def get_is_favor(self,obj):# 1. 用户未登录user_object = self.context['request'].userif not user_object:return False# 2. 用户已登录exists = models.NewsFavorRecord.objects.filter(user=user_object,news=obj).exists()return exists

3.5 自定义返回数据格式---models添加方法

class Release(BaseModel):"""发布"""position = models.CharField(verbose_name='位置', max_length=225, blank=True, null=True)content = models.CharField(verbose_name='内容', max_length=225)# 这三个存数量，做一个优化release_up = models.BigIntegerField(verbose_name='新闻点赞数量', default=0)watch_num = models.BigIntegerField(verbose_name='观看人数数量', default=0)release_num = models.BigIntegerField(verbose_name='评论数量', default=0)# db_constraint=False db_constraint=False  逻辑上的关联，实质上没有外键联系，增删不会受外键影响，orm查询不影响userinfo = models.ForeignKey(verbose_name='用户', to='UserInfo', on_delete=models.DO_NOTHING, db_constraint=False)topic = models.ForeignKey(verbose_name='话题', to='Topic', on_delete=models.DO_NOTHING, db_constraint=False,null=True, blank=True, related_name='topic_release')# 返回图片@propertydef cover_msg_url(self):# 每一个对象走一遍msg_url = self.media.all().filter(is_show=True, is_delete=False).first().cosUrl# print(msg_url)return msg_url################序列化器####################
class ReleaseModelSerializer(serializers.ModelSerializer):"""话题序列化器"""class Meta:model = models.Releasefields = ['id', 'cover_msg_url']

3.6 1.6 在序列化器里面使用序列化器

class AuctionItem(serializers.ModelSerializer):"""拍卖场详细--拍品 序列化器嵌套"""is_deposit = serializers.SerializerMethodField()class Meta:model = models.AuctionItemfields = ['id', 'uid', 'title', 'cover', 'is_deposit','start_price', 'reserve_price', 'highest_price','unit',]# 是否缴纳单品保证金# 是否缴纳全场/单品保证金def get_is_deposit(self, obj):# 判断是否登录user = self.context['request'].userif not user:return False# 如果是全场，单品为null# 判断是否交了保障金，True/Falseexist = models.DepositRecord.objects.filter(user=user, item=obj, status=2).exists()return existclass AuctionDetailModelSerializer(serializers.ModelSerializer):"""拍卖场详细"""status = serializers.CharField(source='get_status_display')auction_item = serializers.SerializerMethodField()preview_start_time = serializers.DateTimeField(format='%Y-%m-%d %H:%M', read_only=True)preview_end_time = serializers.DateTimeField(format='%Y-%m-%d %H:%M', read_only=True)auction_start_time = serializers.DateTimeField(format='%Y-%m-%d %H:%M', read_only=True)auction_end_time = serializers.DateTimeField(format='%Y-%m-%d %H:%M', read_only=True)is_deposit = serializers.SerializerMethodField()class Meta:model = models.Auctionfields = ['id', 'status', 'title', 'cover', 'is_deposit', 'preview_start_time','preview_end_time', 'auction_start_time', 'auction_end_time','look_count', 'auction_item']def get_auction_item(self, obj):# 查询拍卖品item_list = models.AuctionItem.objects.filter(auction=obj)# 把request传入上一个序列化器，序列化器里面使用序列化器ser = AuctionItem(instance=item_list, many=True, context=self.context)return ser.data# 是否缴纳全场/单品保证金def get_is_deposit(self, obj):# 判断是否登录user = self.context['request'].userif not user:return False# 如果是全场，单品为null# 判断是否交了保障金，True/Falseexist = models.DepositRecord.objects.filter(user=user, item__isnull=True, status=2).exists()return exist

4. 序列化的方法中获取request||context存值

class TestSER(serializers.ModelSerializer):title = serializers.SerializerMethodField()class Meta:model = models.Topicfields = "__all__"def get_title(self,obj):request = self.context['request']# serializer放值
# serdef _give_data(self, user_obj, token):"""在context赋值，用于返回前端"""self.context['user_id'] = user_obj.idself.context['username'] = user_obj.usernameself.context['phone'] = user_obj.phoneself.context['avatar'] = user_obj.avatarself.context['bucket'] = user_obj.bucketself.context['region'] = user_obj.regionself.context['balance'] = user_obj.balanceself.context['token'] = token
# view
from rest_framework import status
from rest_framework.response import Response
from rest_framework.generics import RetrieveAPIView, CreateAPIViewfrom api.serializer.account import LoginRegisterModelSerializerclass LoginRegisterAPIView(RetrieveAPIView, CreateAPIView):"""登录注册视图"""# post请求进行authentication_classes = []def post(self, request, *args, **kwargs):ser = LoginRegisterModelSerializer(data=request.data)if ser.is_valid():# 获取数据返回result = {"status": 1000,"data": {"user_id": ser.context.get('user_id'),"username": ser.context.get('username'),"phone": ser.context.get('phone'),"avatar": ser.context.get('avatar'),"bucket": ser.context.get('bucket'),"region": ser.context.get('region'),"balance": ser.context.get('balance'),"token": ser.context.get('token'),}}return Response(data=result, status=status.HTTP_200_OK)error = ser.errorsreturn Response(data=error, status=status.HTTP_400_BAD_REQUEST)

5. 序列化器里面使用序列化器，如果最上面的，想要使用request的话，是下面的序列化器，传过去的

  ser = AuctionItem(instance=item_list, many=True, context=self.context)

6. 在局部钩子里面拿到其他的字段

    def validate_price(self, attrs):# initial_data--在局部钩子里面，获取其他的字段item_id = self.initial_data.get('item')return attrs

7. 聚合

class BidRecordModelSerializer(serializers.ModelSerializer):status = serializers.CharField(source='get_status_display', read_only=True)username = serializers.CharField(source='user.nickName', read_only=True)id = serializers.CharField(read_only=True)class Meta:model = models.BidRecordfields = ['id', 'status', 'item', 'price', 'username']def validate_item(self, attrs):# item传的就是id,但被反射成立对象exist = models.AuctionItem.objects.filter(id=attrs.id, status=3).exists()if not exist:raise serializers.ValidationError('当前商品未开始竞拍，请等待！')def validate_price(self, attrs):# 底价/最高价/加价幅度 item---这里是iditem_id = self.initial_data.get('item')auction_obj = models.AuctionItem.objects.filter(id=item_id).first()if int(attrs) < auction_obj.start_price:raise serializers.ValidationError('价格必须比低价高！')# 1. 去出价表，查出最新最大的一条价格记录# 2. 当前价格与查询的价格进行比较，from django.db.models import Max# 获取前端传送改过来的item---initial_data# 进行聚合，求出最大值，{'max_price':1200}old_price = models.BidRecord.objects.filter(status=1, item_id=item_id).aggregate(max_price=Max('price'))['max_price']# 4. 如果比查询出来的小，异常if int(attrs) < old_price:raise serializers.ValidationError('出价不能比当前价格小！')# 3. 如果不是加价幅度，异常if int(attrs) % auction_obj.unit != 0:raise serializers.ValidationError('请按照加价幅度出价！')return attrs

8. 分组

 from django.db.models import Max# 每条二级评论的id的最大值# <QuerySet [{'reply_id': 7, 'max_id': 15}, {'reply_id': 8, 'max_id': 11}, {'reply_id': 9, 'max_id': 12}]>result = models.Comment.objects.filter(is_show=True, is_delete=False, depth=2,reply_id__in=first_id_list).values('reply_id').annotate(max_id=Max('id'))

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二进制序列化器、XML序列化器、Json序列化器
二进制序列化器.XML序列化器.Json序列化器序列化是将对象的状态信息转换未可以存储或传输的形式的过程.在序列化期间,对象将其当前状态写入到临时或持久性存储区.以后,可以通过从存储区读取或反序列化 ...
客户端序列码生成_Django REST Framework教程(2): 序列化器介绍及开发基于函数视图的API...
在上篇文章中,我们已经介绍了为什么要学习DRF,什么是序列化以及什么是符合RESTful规范的Web API.在本篇文章中我们将以博客为例,使用DRF提供的序列化器(Serializers类)开发两个 ...
魔方APP项目-04-用户模块API接口、Marshmallow，基本构造器(Schema)，Schema数据序列化、Schema数据反序列化、反序列化对数据验证、模型构造器(ModelSchema)
用户模块当前开发的项目属于社交类型项目,所以关于用户的信息和功能直接贯穿了整个项目.所以此处实现用户模块功能,我们先把用户基本信息构建起来,并通过基本信息实现用户注册登录相关功能,后面遇到业务再继续 ...

def序列化器---视图序列化反序列化