序列化器Serializer + 反序列化 + 局部 全局 函数钩子 + APIview（五大接口 增删改单群查） + ModelSerializer +自己封装的response

# utils.py
# 自己封装的response 未继承 Response

class APIResponse():
    def __init__(self):
        self.msg = '成功'
        self.code = 100

    @property
    def get_dic(self):
        return self.__dict__

models.py

from django.db import models


class Book(models.Model):
    auth = models.CharField(max_length=32)
    publish = models.CharField(max_length=32)
    price = models.DecimalField(max_digits=5, decimal_places=2)
    add = models.CharField(max_length=32)


# url.py

from django.contrib import admin
from django.urls import path, re_path

from app01 import views

urlpatterns = [
    path('admin/', admin.site.urls),

    # 单查 put
    re_path(r'books/(?P<pk>\d+)', views.BookView.as_view()),

    # BookModelSerializerView -- put
    re_path(r'book/(?P<pk>\d+)', views.BookModelSerializerView.as_view()),

    # 群查 post
    path(r'books/', views.BooksView.as_view()),

]

view.py 

'''
一：
序列化器的使用
二：
反序列化器的使用
三:
put
四：
delete
一：
群查 many=Ture
post
删除
自己的 response
二：
ModelSerializer
三：
serializer高级使用
四：
source三种用法
'''

from django.shortcuts import render

from rest_framework.views import APIView
from rest_framework.response import Response

from . import utils
from . import models
from . import serializer

dic = {
    'code': '100',
    'msg': '',
}


class BookView(APIView):
    # 单查
    def get(self, request, pk):
　　　　　# 查询到当前pk值得book对象
        book = models.Book.objects.filter(pk=pk).first()
　　　　　# 把当前pk得book 序列化 
        book_ser = serializer.BookSerializer(instance=book)
        dic['code'] = '100'
        dic['msg'] = '成功'
        dic['data'] = book_ser.data
　　　　　# 序列化成功以后会返回序列化数据 既 boook_ser.data
        return Response(data=dic)

    # 修改
    def put(self, request, pk):
        # 查询到当前想要修改的对象
        book = models.Book.objects.filter(pk=pk).first()
        # 实例化对象 instance--将要修改的对象 data----修改的数据 由前端传过来
        book_ser = serializer.BookSerializer(instance=book, data=request.data)
　　　　　　# 是否校验成功
        if book_ser.is_valid():
            # book_ser-- 校验后的数据
　　　　　　　# 保存校验完成的数据
            book_ser.save()
            dic['code'] = '100'
            dic['msg'] = '成功'
            dic['data'] = book_ser.data
        else:
            dic['code'] = '0'
            dic['msg'] = '失败'
            dic['data'] = book_ser.errors
        return Response(data=dic)

    def delete(self, request, pk):
        models.Book.objects.filter(pk=pk).delete()
        dic['code'] = '100'
        dic['msg'] = '成功'
        return Response(data=dic)


class BooksView(APIView):
    # 群查接口--API
    def get(self, request):
　　　　
        books = models.Book.objects.all()
　　　　# many 群查的标准 有many去控制生成的对象
        books_serializer = serializer.BookSerializer(books, many=True)
        dic['code'] = '100'
        dic['msg'] = '成功'
        dic['data'] = books_serializer.data
        return Response(data=dic)

    # # 增加
    # def post(self, request):
    #     book_serializer = serializer.BookSerializer(data=request.data)
    #     if book_serializer.is_valid():
    #         book_serializer.save()
    #         response = APIResponse()
    #         dic['code'] = '100'
    #         dic['msg'] = '成功'
    #         dic['data'] = book_serializer.data
    #     else:
    #         dic['code'] = '0'
    #         dic['msg'] = '失败'
    #         dic['data'] = book_serializer.errors
    #     return Response(data=dic)

    # 增加
    def post(self, request):
        book_serializer = serializer.BookSerializer(data=request.data)
        if book_serializer.is_valid():
            book_serializer.save()
            response = utils.APIResponse()
            response.data = book_serializer.data
        else:
            response = utils.APIResponse()
            response.msg = '失败'
            response.code = 0
            response.data = book_serializer.errors
        return Response(data=response.get_dic)


class BookModelSerializerView(APIView):
    def put(self, request, pk):
        books = models.Book.objects.filter(pk=pk).first()
        bms = serializer.BookModelSerializer(instance=books, data=request.data)
        if bms.is_valid():
            bms.save()
            response = utils.APIResponse()
            response.data = bms.data

        else:
            response = utils.APIResponse()
            response.code = 0
            response.msg = '失败'
            response.data = bms.errors
        return Response(response.get_dic)

serializer.py

from rest_framework import serializers
from rest_framework.exceptions import ValidationError

from . import models


def check_publish(data):
    if data.endswith('sb') or data.startswith('sb'):
        raise ValidationError('出版社不能出现sb或带有歧义的字符')
    return data


class BookSerializer(serializers.Serializer):
    id = serializers.CharField(read_only=True)
    publish = serializers.CharField(min_length=2, validators=[check_publish])
    # publish = serializers.CharField(min_length=2)
    price = serializers.CharField()
    add = serializers.CharField()
　　# 局部钩子 validate_字段名 data --- 字段（想要检验的字段名） 
    def validate_price(self, data):
        if float(data) < 0:
            raise ValidationError('图书价格不可以低于0')
        return data
　　# 全局钩子 attrs -- 想要序列化和反序列化的数据 是一个字典
    def validate(self, attrs):
        publish = attrs.get('publish')
        add = attrs.get('add')
        if publish == add:
            raise ValidationError('图书出版社不能和地址相同')
        return attrs
　　# 继承APIView 如果是put方法的话 需要重写update   instance--book对象 validate_data ---想要修改的数据  
    def update(self, instance, validated_data):
        '''
        :param instance: book对象
        :param validated_data: 修改的数据 request。data
        :return: instance
        '''

        instance.publish = validated_data.get('publish')
        instance.price = validated_data.get('price')
        instance.add = validated_data.get('add')
        instance.save()
        return instance
# 继承APIView 如果是post 需要重写create方法
    def create(self, validated_data):
        instance = models.Book.objects.create(**validated_data)
        return instance


# 序列化器继承 ModelSerializer 对于post put 将不需要重写update create  
class BookModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Book
        # fields = '__all__'
        fields = ['price', 'add']

        extra_kwargs = {
            'add': {'max_length': 8}
        }

    def validate_price(self, data):
        if float(data) < 0:
            raise ValidationError('图书价格不可以低于0')
        return data