August Rush

class BooksInfo(models.Model):
    title = models.CharField(max_length=20, verbose_name='名称')
    pub_date = models.DateField(verbose_name='发布日期')
    read = models.IntegerField(default=0, verbose_name="阅读量")
    comment = models.IntegerField(default=0, verbose_name="评论量")
    is_delete = models.BooleanField(default=False, verbose_name='逻辑删除')

class BooksInfoSerializer(serializers.Serializer):
    id = serializers.IntegerField(read_only=True)
    title = serializers.CharField(label='名称', max_length=20)
    pub_date = serializers.DateField(label='发布日期')
    read = serializers.IntegerField(label='阅读量', required=False)
    comment = serializers.IntegerField(label="评论量", required=False)

Serializer(instance=None, data=empty, **kwarg)

serializer = AccountSerializer(account, context={'request': request})

# 先查询出一个图书对象
from books.models import BooksInfo

book = BooksInfo.objects.get(id=1)

# 构造序列化器对象
from books.serializers import BooksInfoSerializer

serializer = BooksInfoSerializer(book)

# 获取序列化数据
print(serializer.data)
# {'id': 1, 'title': '三国演义', 'pub_date': '1969-01-23', 'read': 0, 'comment': 0}

# 如果被序列化的是包含多条数据的，可以通过添加many=True参数补充说明
books = BooksInfo.objects.all()
serializer = BooksInfoSerializer(books, many=True)
print(serializer.data)
'''
[OrderedDict([('id', 1), ('title', '三国演义'), ('pub_date', '1969-01-23'), ('read', 0), ('comment', 0)]), OrderedDict([('id', 2), ('title', '西游记'), ('pub_date', '2021-08-02'), ('read', 0), ('comment', 0)])]
'''

class HeroInfoSerializer(serializers.Serializer):
    GENDER_CHOICES = (
        (0, 'male'),
        (1, 'female')
    )
    id = serializers.IntegerField(read_only=True)
    name = serializers.CharField(label='名称', max_length=20)
    gender = serializers.ChoiceField(label='性别', default=0, choices=GENDER_CHOICES)
    desc = serializers.CharField(label='描述信息', max_length=200, allow_null=True, required=False)
    is_delete = serializers.BooleanField(default=False, label='逻辑删除', required=False)

hero_book = serialziers.PrimaryKeyRelatedField(label='图书', read_only=True)
# 或
hero_book = serialziers.PrimaryKeyRelatedField(label='图书', queryset=BookInfo.objects.all())

from books.models import HeroInfo, BooksInfo
from books.serialziers import HeroInfoSerializer, BooksInfoSerializer
hero = HeroInfo.objects.get(id=1)
serializer = HeroInfoSerializer(instance=hero)
serializer.data
# {'id': 1, 'name': '郭靖', 'gender': 1, 'desc': '降龙十八掌', 'is_delete': False, 'hero_book': 3}

hero_book = serialziers.StringRelatedField(label='图书')

# {'id': 1, 'name': '郭靖', 'gender': 1, 'desc': '降龙十八掌', 'is_delete': False, 'hero_book': '天龙八部'}

hero_book = serializers.HyperlinkedRelatedField(label='图书', read_only=True, view_name='book_detail')

class HeroDetailAPIView(APIView):
    def get(self, request, pk):
        hero = HeroInfo.objects.get(id=pk)
        serialzier = HeroInfoSerializer(instance=hero, context={'request': request})
        return Response(serialzier.data)

{"id":1,"name":"郭靖","gender":1,"desc":"降龙十八掌","is_delete":false,"hero_book":"http://127.0.0.1:8000/book/3/"}

hero_book = serializers.SlugRelatedField(label='图书', read_only=True, slug_field='title')

{"id":1,"name":"郭靖","gender":1,"desc":"降龙十八掌","is_delete":false,"hero_book":"射雕英雄传"}

hero_book = BooksInfoSerializer()

{"id":1,"name":"郭靖","gender":1,"desc":"降龙十八掌","is_delete":false,"hero_book":{"id":3,"title":"射雕英雄传","pub_date":"1980-05-01","read":12,"comment":34,"heroinfo_set":["郭靖","黄蓉","黄药师","欧阳锋","梅超风"]}}

class BookRelateField(serializers.RelatedField):
  def to_respresentation(self, value):
    return f'{value.id}, {value.title}, {value.pub_date}'

hero_book = BookRelateField(read_only=True)

{"id":1,"name":"郭靖","gender":1,"desc":"降龙十八掌","is_delete":false,"hero_book":"3, 射雕英雄传, 1980-05-01"}

from books.models import BooksInfo
from books.serialziers import BooksInfoSerializer

# 数据校验无误
data = {'title':'流畅的Python', 'pub_date':'2010-01-03'}

serializer = BooksInfoSerializer(data=data)

serializer.is_valid()  # 返回True

serializer.errors  # {}

serializer.validated_data  # OrderedDict([('title', '流畅的Python'), ('pub_date', datetime.date(2010, 1, 3))])

# 数据校验失败
data = {'title':'流畅的Python'}

serializer = BooksInfoSerializer(data=data)

serializer.is_valid()  # 返回False

serializer.errors  # {'pub_date': [ErrorDetail(string='该字段是必填项。', code='required')]}

serializer.validated_data  # {}

class BooksInfoSerializer(serializers.Serializer):
    """图书数据序列化器"""
    ...

    def validate_title(self, value):
        if 'python' not in value.lower():
            raise serializers.ValidationError("图书不是关于python的")
        return value

from booktest.serializers import BooksInfoSerializer
data = {'btitle': 'august'}
serializer = BooksInfoSerializer(data=data)
serializer.is_valid()  # False   
serializer.errors
#  {'btitle': [ErrorDetail(string='图书不是关于python的', code='invalid')]}

class BooksInfoSerializer(serializers.Serializer):
    """图书数据序列化器"""
    ...

    def validate(self, attrs):
        try:
            if attrs['read'] < attrs['comment']:
                raise ValidationError('评论量不能大于阅读量')
        except KeyError:
            return attrs
        else:
            return attrs

from booktest.serializers import BookInfoSerializer
data = {'btitle': '流畅的Python', 'bread': 10, 'bcomment': 20}
s = BookInfoSerializer(data=data)
s.is_valid()  # False
s.errors
#  {'non_field_errors': [ErrorDetail(string='阅读量小于评论量', code='invalid')]}

class BooksInfoSerializer(serializers.Serializer):
    """图书数据序列化器"""
    ...

    def validate(self, attrs):
        attrs['hello'] = "hello world"
        return attrs

data = {'title':'流畅的Python','pub_date':'2010-10-23', 'read':12, 'comment':1}
serializer = BooksInfoSerializer(data=data)
serializer.is_valid()  # True
serializer.validated_data
# OrderedDict([('title', '流畅的Python'), ('pub_date', datetime.date(2010, 10, 23)), ('read', 12), ('comment', 1), ('hello', 'hello world!')])

def validate_read(value):
    if int(value) < 0:
        raise ValidationError('阅读量不能小于0')
    return value

class BooksInfoSerializer(serializers.Serializer):
    id = serializers.IntegerField(read_only=True)
    title = serializers.CharField(label='名称', max_length=20)
    pub_date = serializers.DateField(label='发布日期')
    read = serializers.IntegerField(label='阅读量', required=False, validators=(validate_read, ))
    comment = serializers.IntegerField(label="评论量", required=False)

from booktest.serializers import BookInfoSerializer
data = {"title": "流畅的Python", "pub_date": "1987-11-11", "read": -1, "comment": 24}
serializer = BookInfoSerializer(data=data)
serializer.is_valid()  # False   
serializer.errors
#  {'read': [ErrorDetail(string='阅读量不能小于0', code='invalid')]}

class BooksInfoSerializer(serializers.Serializer):
    """图书数据序列化器"""
    ...

    def create(self, validated_data):
        """新建 validated_data:->字典"""
        title = validated_data.get('title')
        pub_date = validated_data.get('pub_date')
        read = validated_data.setdefault('read', 0)
        comment = validated_data.setdefault('comment', 0)
        return BookInfo.objects.create(title=title, pub_date=pub_date, read=read, comment=comment)
        # 如果validated_data没有不属于当前模型的字段时可用下面写法
        # return BookInfo.objects.create(**validated_data)

    def update(self, instance, validated_data):
        """更新，instance为要更新的对象实例"""
        instance.btitle = validated_data.get('btitle', instance.btitle)
        instance.bpub_date = validated_data.get('bpub_date', instance.bpub_date)
        instance.bread = validated_data.get('bread', instance.bread)
        instance.bcomment = validated_data.get('bcomment', instance.bcomment)
        return instance

book = serializer.save()

serializer.save(owner=request.user)

# Update `comment` with partial data
serializer = CommentSerializer(comment, data={'content': u'foo bar'}, partial=True)