Django REST framework
Django REST framework官方文档:点击 中文文档:点击
- 安装djangorestframework:pip3 install djangorestframework (pip3 list 查看详情和版本信息)
- 注册rest_framework(settings.py)


INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'app01',
'rest_framework',
]
DRF序列化
做前后端分离的项目,前后端交互一般都选择JSON数据格式,JSON是一个轻量级的数据交互格式。后端给前端数据的时候都要转成json格式,那就需要对从数据库拿到的数据进行序列化。
要用DRF的序列化,就要遵循人家框架的一些标准
- 声明序列化类(app01目录下新建serializers.py文件)
- Django CBV继承类是View,现在DRF要用APIView
- Django中返回的时候用HTTPResponse,JsonResponse,render ,DRF用Response
-
DRF反序列化
- 当前端给后端发post的请求的时候,前端给后端传过来的数据,要进行一些校验然后保存到数据库。
- 这些校验以及保存工作,DRF的Serializer也提供了一些方法了,
- 首先要写反序列化用的一些字段,有些字段要跟序列化区分开,
- Serializer提供了.is_valid()和.save()方法
一、Serializer
1、声明序列化类(app01中serializers.py)


from rest_framework import serializers
from .models import Book
class PublisherSerializer(serializers.Serializer):
id = serializers.IntegerField()
title = serializers.CharField(max_length=32)
class AuthorSerializer(serializers.Serializer):
id = serializers.IntegerField()
name = serializers.CharField(max_length=32)
book_obj = {
"title": "Alex的使用教程",
"w_category": 1,
"pub_time": "2018-10-09",
"publisher_id": 1,
"author_list": [1, 2]
}
data = {
"title": "Alex的使用教程2"
}
#3.1 验证器 validators 定义函数写验证规则
def my_validate(value):
if "敏感信息" in value.lower():
raise serializers.ValidationError("不能含有敏感信息")
else:
return value
class BookSerializer(serializers.Serializer):
id = serializers.IntegerField(required=False) #required=False 不需要校验
title = serializers.CharField(max_length=32, validators=[my_validate]) #3.2 验证器 validators用自定义的验证方法,比validate_title权重高
CHOICES = ((1, "Python"), (2, "Go"), (3, "Linux"))
category = serializers.ChoiceField(choices=CHOICES, source="get_category_display", read_only=True) #choices
w_category = serializers.ChoiceField(choices=CHOICES, write_only=True)
pub_time = serializers.DateField()
#外键关系的序列化
publisher = PublisherSerializer(read_only=True) #read_only=True只序列化的时候用
publisher_id = serializers.IntegerField(write_only=True) #ForeignKey #write_only=True只反序列化的时候用
#ManyToMany的序列化
author = AuthorSerializer(many=True, read_only=True) #ManyToManyField
author_list = serializers.ListField(write_only=True)
#新建
def create(self, validated_data):
book = Book.objects.create(title=validated_data["title"], category=validated_data["w_category"],
pub_time=validated_data["pub_time"], publisher_id=validated_data["publisher_id"])
book.author.add(*validated_data["author_list"])
return book
#修改
def update(self, instance, validated_data):
instance.title = validated_data.get("title", instance.title)
instance.category = validated_data.get("w_category", instance.w_category)
instance.pub_time = validated_data.get("pub_time", instance.pub_time)
instance.publisher_id = validated_data.get("publisher_id", instance.publisher_id)
if validated_data.get("author_list"):
instance.author.set(validated_data["author_list"])
instance.save()
return instance
#验证
#1、单个字段的验证
def validate_title(self, value):
if "python" not in value.lower():
raise serializers.ValidationError("标题必须含有python")
return value
#2、多个字段的验证
def validate(self, attrs):
if attrs["w_category"] == 1 and attrs["publisher_id"] == 1:
return attrs
else:
raise serializers.ValidationError("分类以及标题不符合要求")
#3、验证器 validators
2、用声明的序列化类去序列化(app01中views.py)


from .models import Book
from rest_framework.views import APIView
from rest_framework.viewsets import GenericViewSet
from rest_framework.response import Response
from .serializers import BookSerializer
class BookView(APIView):
def get(self, request):
# book_obj = Book.objects.first()
# ret = BookSerializer(book_obj)
book_list = Book.objects.all()
ret = BookSerializer(book_list, many=True) #多个ManyToManyField
return Response(ret.data)
def post(self, request):
print(request.data)
serializer = BookSerializer(data=request.data)
if serializer.is_valid():
serializer.save()
return Response(serializer.data)
else:
return Response(serializer.errors)
class BookEditView(APIView):
def get(self, request, id):
book_obj = Book.objects.filter(id=id).first()
ret = BookSerializer(book_obj)
return Response(ret.data)
def put(self, request, id):
book_obj = Book.objects.filter(id=id).first()
serializer = BookSerializer(book_obj, data=request.data, partial=True) #partial=True允许部分进行更新
if serializer.is_valid():
serializer.save()
return Response(serializer.data)
else:
return Response(serializer.errors)
def delete(self, request, id):
book_obj = Book.objects.filter(id=id).first()
book_obj.delete()
return Response("")
二、ModelSerializer
- 跟模型紧密相关的序列化器
- 根据模型自动生成一组字段
- 默认实现了.update()以及.create()方法
1、定义一个ModelSerializer序列化器(app01中serializers.py)


from rest_framework import serializers
from .models import Book
# 验证器 validators 定义函数写验证规则
def my_validate(value):
if "敏感信息" in value.lower():
raise serializers.ValidationError("不能含有敏感信息")
else:
return value
class BookSerializer(serializers.ModelSerializer):
#category = serializers.CharField(source="get_category_display",read_only=True) #自定制
category_display = serializers.SerializerMethodField(read_only=True) # SerializerMethodField
publisher_info = serializers.SerializerMethodField(read_only=True)
authors = serializers.SerializerMethodField(read_only=True)
def get_category_display(self, obj):
return obj.get_category_display()
def get_authors(self, obj):
# obj是当前序列化的book对象
#外键关联的对象有很多字段是用不到的~都传给前端会有数据冗余~就需要去定制序列化外键对象的哪些字段~~
authors_query_set = obj.author.all()
return [{"id": author_obj.id, "name": author_obj.name} for author_obj in authors_query_set]
def get_publisher_info(self, obj):
# obj 是我们序列化的每个Book对象
# 外键关联的对象有很多字段是用不到的~都传给前端会有数据冗余~就需要去定制序列化外键对象的哪些字段~~
publisher_obj = obj.publisher
return {"id": publisher_obj.id, "title": publisher_obj.title}
class Meta:
model = Book
# fields = ["id", "title", "pub_time"]
# exclude = ["user"]
# 包含某些字段 排除某些字段
fields = "__all__"
# depth = 1 #depth 代表找嵌套关系的第1层
#注意:当序列化类MATE中定义了depth时,这个序列化类中引用字段(外键)则自动变为只读
#read_only_fields = ["id", "category_display", "publisher_info", "authors"]
extra_kwargs = {"category": {"write_only": True}, "publisher": {"write_only": True},
"author": {"write_only": True},"title": {"validators": [my_validate,]}}


from rest_framework import serializers
from api import models
class CourseModelSerializer(serializers.ModelSerializer):
# price = serializers.SerializerMethodField()
# learn_num = serializers.SerializerMethodField()
learn_num = serializers.IntegerField(source='order_details.count')
course_detail_id = serializers.IntegerField(source='coursedetail.id')
# def get_price(self, obj):
# # 把所有课程永久有效的价格拿出来
# price_obj = obj.price_policy.all().filter(valid_period=999).first()
# return price_obj.price
# def get_learn_num(self, obj):
# return obj.order_details.count()
# 修改序列化结果的终极方法
def to_representation(self, instance):
# 调用父类的同名方法把序列化的结果拿到
data = super().to_representation(instance)
# 针对序列化的结果做一些自定制操作
# 判断当前这个课程是否有永久有效的价格
price_obj = instance.price_policy.all().filter(valid_period=999).first()
if price_obj:
# 有永久有效的价格
data['has_price'] = True
data['price'] = price_obj.price
else:
# 没有永久有效的价格策略
data['has_price'] = False
return data
class Meta:
model = models.Course
fields = '__all__'
class CourseCategoryModelSerializer(serializers.ModelSerializer):
class Meta:
model = models.CourseCategory
fields = '__all__'
三、Serializer和ModelSerializer的区别
四、JsonResponse和Django序列化


#app01中models.py
from django.db import models
__all__ = ["Book", "Publisher", "Author"]
class Book(models.Model):
title = models.CharField(max_length=32, verbose_name="图书名称")
CHOICES = ((1, "Python"), (2, "Go"), (3, "Linux"))
category = models.IntegerField(choices=CHOICES, verbose_name="图书的类别")
pub_time = models.DateField(verbose_name="图书的出版日期")
publisher = models.ForeignKey(to="Publisher", on_delete=None)
author = models.ManyToManyField(to="Author")
def __str__(self):
return self.title
class Meta:
verbose_name_plural = "01-图书表"
db_table = verbose_name_plural
class Publisher(models.Model):
title = models.CharField(max_length=32, verbose_name="出版社的名称")
def __str__(self):
return self.title
class Meta:
verbose_name_plural = "02-出版社表"
db_table = verbose_name_plural
class Author(models.Model):
name = models.CharField(max_length=32, verbose_name="作者的姓名")
def __str__(self):
return self.name
class Meta:
verbose_name_plural = "03-作者表"
db_table = verbose_name_plural
#DRFDemo中urls.py
from django.contrib import admin
from django.urls import path, include
urlpatterns = [
path('admin/', admin.site.urls),
path('books/', include("SerDemo.urls")),
]
#app01中urls.py
from django.urls import path, include
from .views import BookView, BookEditView
urlpatterns = [
path('list', BookView.as_view()),
path('retrieve/<int:id>', BookEditView.as_view()),
]


#app01/views.py
from django.views import View
from django.http import HttpResponse, JsonResponse
from django.core import serializers
from .models import Book, Publisher
class BookView(View):
#第一版 用.values JsonResponse实现序列化
def get(self, request):
book_list = Book.objects.values("id", "title", "category", "pub_time", "publisher")
book_list = list(book_list)
# 如果需要取外键关联的字段信息 需要循环获取外键 再去数据库查然后拼接成想要的
ret = []
for book in book_list:
publisher_id = book["publisher"]
publisher_obj = Publisher.objects.filter(id=publisher_id).first()
book["publisher"] = {
"id": publisher_id,
"title": publisher_obj.title
}
ret.append(book)
# ret = json.dumps(book_list, ensure_ascii=False)
# return HttpResponse(ret) #时间
return JsonResponse(ret, safe=False, json_dumps_params={"ensure_ascii": False})
#第二版 用django serializers实现序列化
# 能够得到要的效果,但是结构有点复杂,而且choices不能显示对应的文本
def get(self, request):
book_list = Book.objects.all()
ret = serializers.serialize("json", book_list, ensure_ascii=False)
return HttpResponse(ret)
DRF的视图
- 在Django REST Framework中内置的Request类扩展了Django中的Request类,实现了很多方便的功能--如请求数据解析和认证等。
- 比如,区别于Django中的request从request.GET中获取URL参数,从request.POST中取某些情况下的POST数据。
- 在APIView中封装的request,就实现了请求数据的解析:
- 对于GET请求的参数通过request.query_params来获取。
- 对于POST请求、PUT请求的数据通过request.data来获取。
一、源码查找
- django中写CBV的时候继承的是View,rest_framework继承的是APIView
- 不管是View还是APIView最开始调用的都是as_view()方法。
- APIView继承了View, 并且执行了View中的as_view()方法,最后用csrf_exempt()方法包裹view把view返回了,用csrf_exempt()方法包裹后去掉了csrf的认证。
- 在View中的as_view方法返回了view函数,而view函数执行了self.dispatch()方法,但是这里是APIView调用的,所以先从APIView找dispatch()方法。
- APIView的dispatch()方法中给request重新赋值了
- 去initialize_request中看下把什么赋值给了request,并且赋值给了self.request, 也就是视图中用的request.xxx到底是什么
- 可以看到,这个方法返回的是Request这个类的实例对象,注意看下这个Request类中的第一个参数request,是走django的时候的原来的request
- 去Request这个类里看 这个Request类把原来的request赋值给了self._request, 也就是说以后_request是老的request,新的request是这个Request类
- request.query_params 存放的是get请求的参数 request.data 存放的是所有的数据,包括post请求的以及put,patch请求
- 相比原来的django的request,现在的request更加精简,清晰了
- 框架提供了一个路由传参的方法ViewSetMixin


#1.徒手垒代码阶段
class SchoolView(APIView):
def get(self, request, *args, **kwargs):
query_set = models.School.objects.all()
ser_obj = app01_serializers.SchoolSerializer(query_set, many=True)
return Response(ser_obj.data)
class SchoolDetail(APIView):
def get(self, request, pk, *args, **kwargs):
obj = models.School.objects.filter(pk=pk).first()
ser_obj = app01_serializers.SchoolSerializer(obj)
return Response(ser_obj.data)
#路由
url(r'school/$', views.SchoolView.as_view()),
url(r'school/(?P<pk>\d+)/$', views.SchoolDetail.as_view()),
#2.使用混合类阶段
class SchoolView(GenericAPIView, mixins.ListModelMixin):
queryset = models.School.objects.all()
serializer_class = app01_serializers.SchoolSerializer
def get(self, request, *args, **kwargs):
return self.list(request, *args, **kwargs)
class SchoolDetail(GenericAPIView, mixins.RetrieveModelMixin, mixins.CreateModelMixin):
queryset = models.School.objects.all()
serializer_class = app01_serializers.SchoolSerializer
def get(self, request, pk, *args, **kwargs):
return self.retrieve(request, pk, *args, **kwargs)
def post(self, request, *args, **kwargs):
return self.create(request, *args, **kwargs)
#路由
url(r'school/$', views.SchoolView.as_view()),
url(r'school/(?P<pk>\d+)/$', views.SchoolDetail.as_view()),
# 3.使用通用类
class SchoolView(ListCreateAPIView):
queryset = models.School.objects.all()
serializer_class = app01_serializers.SchoolSerializer
class SchoolDetail(RetrieveUpdateDestroyAPIView):
queryset = models.School.objects.all()
serializer_class = app01_serializers.SchoolSerializer
#路由
url(r'school/$', views.SchoolView.as_view()),
url(r'school/(?P<pk>\d+)/$', views.SchoolDetail.as_view()),
#4.使用视图集
class SchoolView(ModelViewSet):
queryset = models.School.objects.all()
serializer_class = app01_serializers.SchoolSerializer
#路由:
url(r'school/$', views.SchoolView.as_view({
"get": "list",
"post": "create",
})),
url(r'school/(?P<pk>\d+)/$', views.SchoolView.as_view({
'get': 'retrieve',
'put': 'update',
'patch': 'partial_update',
'delete': 'destroy'
})),
#高级路由
from rest_framework.routers import DefaultRouter
router = DefaultRouter()
router.register(r'school', views.SchoolView)
urlpatterns += router.urls
二、ModelViewSet


from django.urls import path, include
from .views import BookView, BookEditView, BookModelViewSet
urlpatterns = [
# path('list', BookView.as_view()),
# path('retrieve/<int:id>', BookEditView.as_view()),
path('list', BookModelViewSet.as_view({"get": "list", "post": "create"})),
path('retrieve/<int:pk>', BookModelViewSet.as_view({"get": "retrieve", "put": "update", "delete": "destroy"})),
]


from .models import Book
from .serializers import BookSerializer
from rest_framework.viewsets import ModelViewSet
class BookModelViewSet(ModelViewSet):
queryset = Book.objects.all()
serializer_class = BookSerializer
#现在的视图就只要写两行就可以了
#注意:用框架封装的视图~url上的那个关键字参数要用pk系统默认的
##path('retrieve/<int:pk>', BookModelViewSet.as_view({"get": "retrieve", "put": "update", "delete": "destroy"})) 用pk
# from rest_framework import views
# from rest_framework import generics
# from rest_framework import mixins
# from rest_framework import viewsets


from .models import Book
from rest_framework.views import APIView
from rest_framework.response import Response
from .serializers import BookSerializer
class GenericAPIView(APIView):
query_set = None
serializer_class = None
def get_queryset(self):
return self.query_set
def get_serializer(self, *args, **kwargs):
return self.serializer_class(*args, **kwargs)
class ListModelMixin(object):
def list(self, request):
queryset = self.get_queryset()
ret = self.get_serializer(queryset, many=True)
return Response(ret.data)
class CreateModelMixin(object):
def create(self, request):
serializer = self.get_serializer(data=request.data)
if serializer.is_valid():
serializer.save()
return Response(serializer.data)
else:
return Response(serializer.errors)
class RetrieveModelMixin(object):
def retrieve(self, request, id):
book_obj = self.get_queryset().filter(id=id).first()
ret = self.get_serializer(book_obj)
return Response(ret.data)
class UpdateModelMixin(object):
def update(self, request, id):
book_obj = self.get_queryset().filter(id=id).first()
serializer = self.get_serializer(book_obj, data=request.data, partial=True)
if serializer.is_valid():
serializer.save()
return Response(serializer.data)
else:
return Response(serializer.errors)
class DestroyModelMixin(object):
def destroy(self, request, id):
book_obj = self.get_queryset().filter(id=id).first()
book_obj.delete()
return Response("")
class ListCreateAPIView(GenericAPIView, ListModelMixin, CreateModelMixin):
pass
class RetrieveUpdateDestroyAPIView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):
pass
# class BookView(GenericAPIView, ListModelMixin, CreateModelMixin):
class BookView(ListCreateAPIView):
query_set = Book.objects.all()
serializer_class = BookSerializer
def get(self, request):
# book_obj = Book.objects.first()
# ret = BookSerializer(book_obj)
# book_list = Book.objects.all()
# book_list = self.get_queryset()
# ret = self.get_serializer(book_list, many=True)
# return Response(ret.data)
return self.list(request)
def post(self, request):
# print(request.data)
# serializer = BookSerializer(data=request.data)
# if serializer.is_valid():
# serializer.save()
# return Response(serializer.data)
# else:
# return Response(serializer.errors)
return self.create(request)
# class BookEditView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):
class BookEditView(RetrieveUpdateDestroyAPIView):
query_set = Book.objects.all()
serializer_class = BookSerializer
def get(self, request, id):
# book_obj = Book.objects.filter(id=id).first()
# ret = BookSerializer(book_obj)
# return Response(ret.data)
return self.retrieve(request, id)
def put(self, request, id):
# book_obj = Book.objects.filter(id=id).first()
# serializer = BookSerializer(book_obj, data=request.data, partial=True)
# if serializer.is_valid():
# serializer.save()
# return Response(serializer.data)
# else:
# return Response(serializer.errors)
return self.update(request, id)
def delete(self, request, id):
# book_obj = Book.objects.filter(id=id).first()
# book_obj.delete()
# return Response("")
return self.destroy(request, id)
# class ViewSetMixin(object):
# def as_view(self):
# """
# 按照我们参数指定的去匹配
# get-->list
# :return:
# """
from rest_framework.viewsets import ViewSetMixin #必须继承ViewSetMixin,路由的as_view方法才可以传参
class ModelViewSet(ViewSetMixin, GenericAPIView, ListModelMixin, CreateModelMixin, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):
pass
#上面封装的所有框架都帮我们封装好了
#from rest_framework.viewsets import ModelViewSet
#注意:用框架封装的视图url上的那个关键字参数要用pk系统默认的
class BookModelViewSet(ModelViewSet):
queryset = Book.objects.all()
serializer_class = BookSerializer
DRF的路由


from django.urls import path, include
from .views import BookView, BookEditView, BookModelViewSet
from rest_framework.routers import DefaultRouter
router = DefaultRouter()
router.register(r"book", BookModelViewSet)
urlpatterns = [
# path('list', BookView.as_view()),
# path('retrieve/<int:id>', BookEditView.as_view()),
#path('list', BookModelViewSet.as_view({"get": "list", "post": "create"})),
#path('retrieve/<int:pk>', BookModelViewSet.as_view({"get": "retrieve", "put": "update", "delete": "destroy"})),
]
urlpatterns += router.urls
#通过框架可以把路由视图都变的非常简单
#但是需要自定制的时候还是需要用APIView写,当不需要那么多路由的时候,也不要用这种路由注册.
DRF的版本
随着项目的更新,版本就越来越多,不可能新的版本出了,以前旧的版本就不进行维护了,就需要对版本进行控制了
一、源码查找
- APIView返回View中的view函数,然后调用dispatch方法,APIView的dispatch方法
- 执行self.initial方法之前是各种赋值,包括request的重新封装赋值
def dispatch(self, request, *args, **kwargs): """ `.dispatch()` is pretty much the same as Django's regular dispatch, but with extra hooks for startup, finalize, and exception handling. """ self.args = args self.kwargs = kwargs request = self.initialize_request(request, *args, **kwargs) self.request = request self.headers = self.default_response_headers # deprecate? try: self.initial(request, *args, **kwargs) ##### ... def initial(self, request, *args, **kwargs): """ Runs anything that needs to occur prior to calling the method handler. """ self.format_kwarg = self.get_format_suffix(**kwargs) # Perform content negotiation and store the accepted info on the request neg = self.perform_content_negotiation(request) request.accepted_renderer, request.accepted_media_type = neg # Determine the API version, if versioning is in use. # 版本控制 # self.determine_version 这个方法是找我们自己定义的版本控制类,没有的话返回(None,None) version, scheme = self.determine_version(request, *args, **kwargs) request.version, request.versioning_scheme = version, scheme ###version版本信息赋值给了 request.version 版本控制方案赋值给了 request.versioning_scheme ###其实这个版本控制方案~就是我们配置的版本控制的类,也就是说,APIView通过这个方法初始化自己提供的组件 ###接下来看看框架提供了哪些版本的控制方法在rest_framework.versioning里,from rest_framework import versioning # Ensure that the incoming request is permitted # 认证 权限 频率组件 self.perform_authentication(request) self.check_permissions(request) self.check_throttles(request) ... def determine_version(self, request, *args, **kwargs): """ If versioning is being used, then determine any API version for the incoming request. Returns a two-tuple of (version, versioning_scheme) """ if self.versioning_class is None: return (None, None) #scheme是我们配置的版本控制类的实例化对象 scheme = self.versioning_class() #返回值scheme.determine_version MyVersion中必须定义determine_version这个方法,从上面可以看出此方法返回版本号version return (scheme.determine_version(request, *args, **kwargs), scheme)
二、使用方法1(URL上携带版本信息的配置)
第1步:settings.py


REST_FRAMEWORK = {
# 默认使用的版本控制类
'DEFAULT_VERSIONING_CLASS': 'rest_framework.versioning.URLPathVersioning',
# 允许的版本
'ALLOWED_VERSIONS': ['v1', 'v2'],
# 版本使用的参数名称
'VERSION_PARAM': 'version',
# 默认使用的版本
'DEFAULT_VERSION': 'v1',
}
第2步:app01中urls.py


urlpatterns = [
url(r"^versions", MyView.as_view()),
url(r"^(?P[v1|v2]+)/test01", TestView.as_view()),
]
第3步:测试视图app01.views.py


class TestView(APIView):
def get(self, request, *args, **kwargs):
print(request.versioning_scheme)
ret = request.version
if ret == "v1":
return Response("版本v1的信息")
elif ret == "v2":
return Response("版本v2的信息")
else:
return Response("根本就匹配不到这个路由")
三、使用方法2(URL过滤条件配置版本信息)
第1步:settings.py


REST_FRAMEWORK = {
"DEFAULT_VERSIONING_CLASS": "utils.version.MyVersion",
# "DEFAULT_VERSIONING_CLASS": "rest_framework.versioning.QueryParameterVersioning",
"DEFAULT_VERSION": "v1",
"ALLOWED_VERSIONS": "v1, v2",
"VERSION_PARAM": "ver"
}
第2步:app01中urls.py


from django.urls import path, include
from .views import DemoView
urlpatterns = [
path(r"", DemoView.as_view()),
]
第3步:utils中version.py


from rest_framework import versioning
class MyVersion(object):
def determine_version(self, request, *args, **kwargs):
# 返回值 给了request.version
# 返回版本号
# 版本号携带在过滤条件 xxxx?version=v1中,版本号在那就去那取值
version = request.query_params.get("version", "v1")
return version
第4步:测试视图app01.views.py


from rest_framework.views import APIView
from rest_framework.response import Response
class DemoView(APIView):
def get(self, request):
print(request.version)
print(request.versioning_scheme)
# 得到版本号 根据版本号的不同返回不同的信息
if request.version == "v1":
return Response("v1版本的数据")
elif request.version == "v2":
return Response("v2版本的数据")
return Response("不存在的版本")
DRF的认证
每次给服务器发请求,由于Http的无状态,导致每次都是新的请求,
服务端需要对每次来的请求进行认证,看用户是否登录,以及登录用户是谁,
服务器对每个请求进行认证的时候,不可能在每个视图函数中都写认证,
一定是把认证逻辑抽离出来,以前我们可能会加装饰器或者中间件。
一、源码查找


def dispatch(self, request, *args, **kwargs):
"""
`.dispatch()` is pretty much the same as Django's regular dispatch,
but with extra hooks for startup, finalize, and exception handling.
"""
self.args = args
self.kwargs = kwargs
request = self.initialize_request(request, *args, **kwargs)
self.request = request
self.headers = self.default_response_headers # deprecate?
try:
self.initial(request, *args, **kwargs)
# Get the appropriate handler method
if request.method.lower() in self.http_method_names:
handler = getattr(self, request.method.lower(),
self.http_method_not_allowed)
else:
handler = self.http_method_not_allowed
response = handler(request, *args, **kwargs)
except Exception as exc:
response = self.handle_exception(exc)
self.response = self.finalize_response(request, response, *args, **kwargs)
return self.response
...
def initialize_request(self, request, *args, **kwargs):
"""
Returns the initial request object.
"""
parser_context = self.get_parser_context(request)
return Request(
request,
parsers=self.get_parsers(),
authenticators=self.get_authenticators(),
negotiator=self.get_content_negotiator(),
parser_context=parser_context
)
def initial(self, request, *args, **kwargs):
"""
Runs anything that needs to occur prior to calling the method handler.
"""
self.format_kwarg = self.get_format_suffix(**kwargs)
# Perform content negotiation and store the accepted info on the request
neg = self.perform_content_negotiation(request)
request.accepted_renderer, request.accepted_media_type = neg
# Determine the API version, if versioning is in use.
# 版本控制
# self.determine_version 这个方法是找我们自己定义的版本控制类,没有的话返回(None,None)
version, scheme = self.determine_version(request, *args, **kwargs)
request.version, request.versioning_scheme = version, scheme
# Ensure that the incoming request is permitted
# 认证 权限 频率组件
self.perform_authentication(request)
self.check_permissions(request)
self.check_throttles(request)
...
def perform_authentication(self, request):
"""
Perform authentication on the incoming request.
Note that if you override this and simply 'pass', then authentication
will instead be performed lazily, the first time either
`request.user` or `request.auth` is accessed.
"""
request.user
...
#去类Request中找user
@property
def user(self):
"""
Returns the user associated with the current request, as authenticated
by the authentication classes provided to the request.
"""
if not hasattr(self, '_user'):
with wrap_attributeerrors():
#__enter__
self._authenticate()
#__exit__
return self._user
...
def _authenticate(self):
"""
Attempt to authenticate the request using each authentication instance
in turn.
"""
#这里的authentications是最开始实例化Request类的时候传过来的
#是调用get_authenticators这个方法,
# 这个方法的返回值是 return [auth() for auth in self,authentication_classes]
#authentication_classes如果我们配置了就用我们配置的,否则就从默认配置文件中读取配置类
#返回的auth()是认证类实例化后的
for authenticator in self.authenticators: #查看authenticators
try:
#也就是说这里的authenticator是认证类实例化后的
#authenticate方法是我们必须去实现的方法
#authenticate的参数self,我们是通过新的request.user进来的,所以这个self就是新的request
user_auth_tuple = authenticator.authenticate(self)
except exceptions.APIException:
self._not_authenticated()
raise
if user_auth_tuple is not None:
self._authenticator = authenticator
#request.user
#request.auth
self.user, self.auth = user_auth_tuple
return
self._not_authenticated()
...
class Request(object):
def __init__(self, request, parsers=None, authenticators=None,
negotiator=None, parser_context=None):
assert isinstance(request, HttpRequest), (
'The `request` argument must be an instance of '
'`django.http.HttpRequest`, not `{}.{}`.'
.format(request.__class__.__module__, request.__class__.__name__)
)
self._request = request
self.parsers = parsers or ()
self.authenticators = authenticators or ()
## authenticators看传参了么
...
def initialize_request(self, request, *args, **kwargs):
"""
Returns the initial request object.
"""
parser_context = self.get_parser_context(request)
return Request(
request,
parsers=self.get_parsers(),
authenticators=self.get_authenticators(), #传参了
negotiator=self.get_content_negotiator(),
parser_context=parser_context
)
...
def get_authenticators(self):
"""
Instantiates and returns the list of authenticators that this view can use.
"""
#self.authentication_classes去配置文件拿所有的认证类
return [auth() for auth in self.authentication_classes]
- APIView的dispatch方法里给request重新赋值了
- APIView的dispatch方法里给执行了initial方法,初始化了版本认证,权限,频率组件,initial方法的参数request是重新赋值后的
- 权限组件返回的是request.user,initial的request是重新赋值之后的,所以这里的request是重新赋值之后的,也就是Request类实例对象, 那这个user一定是一个静态方法.
二、使用方法
1、app01中models.py


# 先在model中注册模型类
# 并且进行数据迁移
from django.db import models
class User(models.Model):
username = models.CharField(max_length=32)
pwd = models.CharField(max_length=16)
token = models.UUIDField()
2、app01中urls.py


from django.urls import path
from .views import DemoView, LoginView, TestView
urlpatterns = [
path(r"login", LoginView.as_view()),
path(r"test", TestView.as_view()),
]
3、app01中views.py


import uuid
from .models import User
from utils.auth import MyAuth
from rest_framework.views import APIView
from rest_framework.response import Response
class LoginView(APIView):
def post(self, request):
username = request.data.get("username")
pwd = request.data.get("pwd")
# 登录成功 生成token 会把token给你返回
token = uuid.uuid4()
User.objects.create(username=username, pwd=pwd, token=token)
return Response("创建用户成功")
#局部视图认证
class TestView(APIView):
authentication_classes = [MyAuth,]
def get(self, request):
print(request.user)
print(request.auth)
user_id = request.user.id
return Response("认证测试")
4、utils中auth.py 写一个认证的类


from rest_framework.exceptions import AuthenticationFailed
from app01.models import User
from rest_framework.authentication import BaseAuthentication
class MyAuth(BaseAuthentication):
def authenticate(self, request):
# 做认证 看他是否登录
# 拿到token,此处是从url过滤条件里拿到token
# 去数据库看token是否合法
# 合法的token能够获取用户信息
token = request.query_params.get("token", "")
if not token:
raise AuthenticationFailed("没有携带token")
user_obj = User.objects.filter(token=token).first()
if not user_obj:
raise AuthenticationFailed("token不合法")
# return (None, None)
return (user_obj, token) #第1个返回值是request.user 第2个返回值是request.auth
5、全局配置认证


REST_FRAMEWORK = {
# "DEFAULT_VERSIONING_CLASS": "utils.version.MyVersion",
"DEFAULT_VERSIONING_CLASS": "rest_framework.versioning.QueryParameterVersioning",
"DEFAULT_VERSION": "v1",
"ALLOWED_VERSIONS": "v1, v2",
"VERSION_PARAM": "ver",
# "DEFAULT_AUTHENTICATION_CLASSES": ["utils.auth.MyAuth", ] #全局配置
}
DRF的权限
对某件事情决策的范围和程度叫做权限
一、源码查找


def check_permissions(self, request):
"""
Check if the request should be permitted.
Raises an appropriate exception if the request is not permitted.
"""
for permission in self.get_permissions():
#permission我们写的权限类的实例对象 MyPermission()
if not permission.has_permission(request, self):
#permission_denied是抛出异常的
#也就是说我们的权限类中必须有has_permission这个方法,否则就抛出异常
self.permission_denied(
#message 定义异常信息
request, message=getattr(permission, 'message', None)
)
- 权限类一定要有has_permission方法,否则就会抛出异常,这也是框架提供的钩子
- rest_framework.permissions这个文件中存放了框架提供的所有权限的方法
- BasePermission 这个是写权限类继承的一个基础权限类
- Python代码是一行一行执行的,那么执行initial方法初始化这些组件的时候 也是有顺序的,版本在前面然后是认证,然后是权限最后是频率
- 版本,认证,权限,频率这几个组件的源码是一个流程
二、使用方法
1、app01中models.py


# 先在model中注册模型类
# 并且进行数据迁移
from django.db import models
class User(models.Model):
username = models.CharField(max_length=32)
pwd = models.CharField(max_length=16)
token = models.UUIDField()
type = models.IntegerField(choices=((1, "vip"), (2, "vvip"), (3, "普通")), default=3)
2、app01中urls.py


from django.urls import path
from .views import DemoView, LoginView, TestView
urlpatterns = [
path(r"login", LoginView.as_view()),
path(r"test", TestView.as_view()),
]
3、app01中views.py


import uuid
from .models import User
from utils.auth import MyAuth
from utils.permission import MyPermission
# Create your views here.
from rest_framework.views import APIView
from rest_framework.response import Response
class DemoView(APIView):
def get(self, request):
return Response("认证demo~")
class LoginView(APIView):
def post(self, request):
username = request.data.get("username")
pwd = request.data.get("pwd")
# 登录成功 生成token 会把token给你返回
token = uuid.uuid4()
User.objects.create(username=username, pwd=pwd, token=token)
return Response("创建用户成功")
class TestView(APIView):
authentication_classes = [MyAuth,]
permission_classes = [MyPermission, ] #局部配置权限
def get(self, request):
print(request.user)
print(request.auth)
user_id = request.user.id
return Response("认证测试")
4、utils中permission.py 写一个权限类


from rest_framework.permissions import BasePermission
class MyPermission(BasePermission):
message = "您没有权限"
def has_permission(self, request, view):
# 判断用户是否有权限
user_obj = request.user
if user_obj.type == 3:
return False
else:
return True
5、全局配置权限


REST_FRAMEWORK = {
# "DEFAULT_VERSIONING_CLASS": "utils.version.MyVersion",
"DEFAULT_VERSIONING_CLASS": "rest_framework.versioning.QueryParameterVersioning",
"DEFAULT_VERSION": "v1",
"ALLOWED_VERSIONS": "v1, v2",
"VERSION_PARAM": "ver",
# "DEFAULT_AUTHENTICATION_CLASSES": ["utils.auth.MyAuth", ] #全局配置
}
REST_FRAMEWORK = {
# "DEFAULT_VERSIONING_CLASS": "utils.version.MyVersion",
# 默认使用的版本控制类
'DEFAULT_VERSIONING_CLASS': 'rest_framework.versioning.URLPathVersioning',
# 允许的版本
"ALLOWED_VERSIONS": "v1, v2",
# 版本使用的参数名称
"VERSION_PARAM": "ver",
# 默认使用的版本
'DEFAULT_VERSION': 'v1',
# 配置全局认证
# "DEFAULT_AUTHENTICATION_CLASSES": ["utils.auth.MyAuth", ] #全局配置
# 配置全局权限
"DEFAULT_PERMISSION_CLASSES": ["utils.permission.MyPermission"]
}
DRF的频率
开放平台的API接口调用需要限制其频率,以节约服务器资源和避免恶意的频繁调用。
一、源码查找


def check_throttles(self, request):
"""
Check if request should be throttled.
Raises an appropriate exception if the request is throttled.
"""
#throttle 配置每个频率控制类的实例化对象 allow_request方法和wait方法
for throttle in self.get_throttles():
if not throttle.allow_request(request, self):
self.throttled(request, throttle.wait())
...
def get_throttles(self):
"""
Instantiates and returns the list of throttles that this view uses.
"""
return [throttle() for throttle in self.throttle_classes]
二、频率组件原理
DRF中的频率控制基本原理是基于访问次数和时间的,当然也可以通过自己定义的方法来实现。
当请求进来,走到频率组件的时候,DRF内部会有一个字典来记录访问者的IP,
以这个访问者的IP为key,value为一个列表,存放访问者每次访问的时间,
{ IP1: [第三次访问时间,第二次访问时间,第一次访问时间],}
把每次访问最新时间放入列表的最前面,记录这样一个数据结构后,通过什么方式限流呢~~
如果我们设置的是10秒内只能访问5次,
-- 1,判断访问者的IP是否在这个请求IP的字典里
-- 2,保证这个列表里都是最近10秒内的访问的时间
判断当前请求时间和列表里最早的(也就是最后的)请求时间的查
如果差大于10秒,说明请求以及不是最近10秒内的,删除掉,
继续判断倒数第二个,直到差值小于10秒
-- 3,判断列表的长度(即访问次数),是否大于我们设置的5次,
如果大于就限流,否则放行,并把时间放入列表的最前面。
三、使用方法
1、app01中views.py


import uuid
from .models import User
from utils.auth import MyAuth
from utils.permission import MyPermission
from utils.throttle import MyThrottle
# Create your views here.
from rest_framework.views import APIView
from rest_framework.response import Response
class LoginView(APIView):
def post(self, request):
username = request.data.get("username")
pwd = request.data.get("pwd")
# 登录成功 生成token 会把token给你返回
token = uuid.uuid4()
User.objects.create(username=username, pwd=pwd, token=token)
return Response("创建用户成功")
class TestView(APIView):
authentication_classes = [MyAuth,]
permission_classes = [MyPermission, ]
throttle_classes = [MyThrottle, ]
def get(self, request):
print(request.user)
print(request.auth)
user_id = request.user.id
return Response("认证测试")
2、utils中throttle.py 写一个频率类


from rest_framework.throttling import BaseThrottle, SimpleRateThrottle
import time
VISIT_RECORD = {}
#自定义的频率限制类
# class MyThrottle(BaseThrottle):
#
# def __init__(self):
# self.history = None
#
# def allow_request(self, request, view):
# # 实现限流的逻辑
# # 以IP限流
# # 访问列表 {IP: [time1, time2, time3]}
# # 1, 获取请求的IP地址
# ip = request.META.get("REMOTE_ADDR")
# # 2,判断IP地址是否在访问列表
# now = time.time()
# if ip not in VISIT_RECORD:
# # --1, 不在 需要给访问列表添加key,value
# VISIT_RECORD[ip] = [now,]
# return True
# # --2 在 需要把这个IP的访问记录 把当前时间加入到列表
# history = VISIT_RECORD[ip]
# history.insert(0, now)
# # 3, 确保列表里最新访问时间以及最老的访问时间差 是1分钟
# while history and history[0] - history[-1] > 60:
# history.pop()
# self.history = history
# # 4,得到列表长度,判断是否是允许的次数
# if len(history) > 3:
# return False
# else:
# return True
#
# def wait(self):
# # 返回需要再等多久才能访问
# time = 60 - (self.history[0] - self.history[-1])
# return time
#使用自带的频率限制类
class MyThrottle(SimpleRateThrottle):
scope = "WD"
def get_cache_key(self, request, view):
# 如果以IP地址做限流返回IP地址
key = self.get_ident(request)
return key
3、全局配置频率


REST_FRAMEWORK = {
# "DEFAULT_VERSIONING_CLASS": "utils.version.MyVersion",
"DEFAULT_VERSIONING_CLASS": "rest_framework.versioning.QueryParameterVersioning",
"DEFAULT_VERSION": "v1",
"ALLOWED_VERSIONS": "v1, v2",
"VERSION_PARAM": "ver",
# "DEFAULT_AUTHENTICATION_CLASSES": ["utils.auth.MyAuth", ] #全局配置
}
REST_FRAMEWORK = {
# "DEFAULT_VERSIONING_CLASS": "utils.version.MyVersion",
# 默认使用的版本控制类
'DEFAULT_VERSIONING_CLASS': 'rest_framework.versioning.URLPathVersioning',
# 允许的版本
"ALLOWED_VERSIONS": "v1, v2",
# 版本使用的参数名称
"VERSION_PARAM": "ver",
# 默认使用的版本
'DEFAULT_VERSION': 'v1',
# 配置全局认证
# "DEFAULT_AUTHENTICATION_CLASSES": ["utils.auth.MyAuth", ] #全局配置
# 配置全局权限
"DEFAULT_PERMISSION_CLASSES": ["utils.permission.MyPermission"],
# 配置自定义频率限制
"DEFAULT_THROTTLE_CLASSES": ["Throttle.throttle.MyThrottle"],
# 配置频率限制
"DEFAULT_THROTTLE_RATES": {
"WD": "3/m" #速率配置每分钟不能超过3次访问,WD是scope定义的值,
}
}
DRF的分页组件
- DRF提供的三种分页:
from rest_framework.pagination import PageNumberPagination, LimitOffsetPagination, CursorPagination
- 全局配置:
REST_FRAMEWORK = { 'PAGE_SIZE': 2 }
- 第1种 PageNumberPagination 看第n页,每页显示n条数据
http://127.0.0.1:8000/book?page=2&size=1
- 第2种 LimitOffsetPagination 在第n个位置 向后查看n条数据
http://127.0.0.1:8000/book?offset=2&limit=1
- 第3种 CursorPagination 加密游标的分页 把上一页和下一页的id记住
http://127.0.0.1:8000/book?page=2&size=1
一、utils中pagination.py(自定义分页类)


from rest_framework.pagination import PageNumberPagination, LimitOffsetPagination, CursorPagination
# class MyPagination(PageNumberPagination):
# # xxxx?page=1&size=2
# page_size = 1 # 每页显示多少条
# page_query_param = "page" # URL中页码的参数
# page_size_query_param = "size" # URL中每页显示条数的参数
# max_page_size = 3 # 最大页码数限制
# class MyPagination(LimitOffsetPagination):
#
# default_limit = 1
# limit_query_param = "limit"
# offset_query_param = "offset"
# max_limit = 3
class MyPagination(CursorPagination):
cursor_query_param = "cursor"
page_size = 2
ordering = "-id"
二、app01中views.py


from django.shortcuts import render
from rest_framework.views import APIView
from rest_framework.response import Response
from SerDemo.models import Book
from SerDemo.serializers import BookSerializer
# Create your views here.
from rest_framework import pagination
from utils.pagination import MyPagination
from rest_framework.generics import GenericAPIView
from rest_framework.mixins import ListModelMixin
# class BookView(APIView):
#
# def get(self, request):
# queryset = Book.objects.all()
# # 1,实例化分页器对象
# page_obj = MyPagination()
# # 2,调用分页方法去分页queryset
# page_queryset = page_obj.paginate_queryset(queryset, request, view=self)
# # 3,把分页好的数据序列化返回
# # 4, 带着上一页下一页连接的响应
# ser_obj = BookSerializer(page_queryset, many=True)
# # 返回带超链接 需返回的时候用内置的响应方法
# return page_obj.get_paginated_response(ser_obj.data)
class BookView(GenericAPIView, ListModelMixin):
queryset = Book.objects.all()
serializer_class = BookSerializer
pagination_class = MyPagination
# self.paginate_queryset(queryset)
def get(self, request):
return self.list(request)
DRF的解析器
- 解析器的作用就是服务端接收客户端传过来的数据,把数据解析成自己想要的数据类型的过程。本质就是对请求体中的数据进行解析。
- 在了解解析器之前要先知道Accept以及ContentType请求头。
- Accept是告诉对方能解析什么样的数据,通常也可以表示想要什么样的数据。
- ContentType是告诉对方我给你的是什么样的数据类型。
- 解析器工作原理的本质 就是拿到请求的ContentType来判断前端给后端数据类型是什么,然后后端去拿相应的解析器去解析数据。
一、Django的解析器
- 请求进来请求体中的数据在request.body中,那也就证明,解析器会把解析好的数据放入request.body
- 在视图中可以打印request的类型,能够知道request是WSGIRequest这个类。
- application/x-www-form-urlencoded不是不能上传文件,是只能上传文本格式的文件
- multipart/form-data是将文件以二进制的形式上传,这样可以实现多种类型的文件上传 一个解析到request.POST, request.FILES中。
- 也就是说之前能在request中能到的各种数据是因为用了不同格式的数据解析器
- Django只能解析cont_type=multipart/form-data 和cont_type=application/x-www-form-urlencoded的数据,不能解析json
二、DRF的解析器
- 在request.data拿数据的时候解析器会被调用
四、DRF的解析器使用方法
1、app01中views.py


from django.shortcuts import render
from django.views import View
from django.http import HttpResponse
from django.core.handlers.wsgi import WSGIRequest
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.negotiation import DefaultContentNegotiation
from rest_framework import parsers
# Create your views here.
class DjangoView(View):
def get(self, request):
print(type(request))
# Request
# request.GET
# request.POST
# json request.body
return HttpResponse("django解析器测试~~")
class DRFView(APIView):
#parser_classes = [parsers.JSONParser, ] #一般不配置
def get(self, request):
# request 重新封装的request Request
# request.data
#
return Response("DRF解析器的测试~~")
DRF的渲染器
渲染器就是友好的展示数据,我们在浏览器中展示的DRF测试的那个页面就是通过浏览器的渲染器来做到的,当然我们可以展示Json数据类型


DEFAULTS = {
# Base API policies
'DEFAULT_RENDERER_CLASSES': (
'rest_framework.renderers.JSONRenderer',
'rest_framework.renderers.BrowsableAPIRenderer',
),
来源:oschina
链接:https://my.oschina.net/u/4386639/blog/3623499