django-rest-framework学习之Quickstart和Serializer--2017年4月10日至12日

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看了极客学院的【Django 开发——API 设计】,因为年代久远版本太老,代码调试了一上午没调试通,决定放弃视频学习,看一些最近的技术博客或者官方文档


 

 上图中可以看出python版本:2.7.5

django版本1.9.4

rest_framework版本3.6.2


 官方文档

http://www.django-rest-framework.org/

使用Django REST framework的原因如下:
 
Web browsable API 对项目来说有很大的可用性;
权限验证包括 OAuth1a and OAuth2;
支持ORM以及non-ORM两个数据源的 Serialization;
若不需要特别强大的功能,直接使用 regular function-based views
扩展文档以及社区讨论;
被大公司使用和信任,比如 Mozilla and Eventbrite;
 

详见git主页:https://github.com/jingbotwins/myTest
 
通过python manage.py createsuperuser添加用户
通过登录页面,登陆之后,可以通过post添加用户
 

curl -H 'Accept: application/json; indent=4' -u admin:password http://127.0.0.1:8000/users/
获取用户列表
 
pip install httpie
http -a admin:password http://127.0.0.1:8000/users/
 

Serialization序列化
实例:creating a simple pastebin code highlighting Web API(创建一个简单的类似于pastebin的代码高亮web api)
【1】开始创建
 
django-admin.py startproject myTest
python manage.py startapp myLesson
 
在myTest/setting.py中INSTALL_APPS添加:
'rest_framework'
'myLesson.apps.MylessonConfig'
 
【2】创建model
在myLesson中添加models.py
 
from django.db import models
from pygments.lexers import get_all_lexers
from pygments.styles import get_all_styles
 
LEXERS = [item for item in get_all_lexers() if item[1]]
LANGUAGE_CHOICES = sorted([(item[1][0], item[0]) for item in LEXERS])
STYLE_CHOICES = sorted((item, item) for item in get_all_styles())
 
 
class MyLesson(models.Model):
    created = models.DateTimeField(auto_now_add=True)
    title = models.CharField(max_length=100, blank=True, default='')
    code = models.TextField()
    linenos = models.BooleanField(default=False)
    language = models.CharField(choices=LANGUAGE_CHOICES, default='python', max_length=100)
    style = models.CharField(choices=STYLE_CHOICES, default='friendly', max_length=100)
 
    class Meta:
        ordering = ('created',)

 

创建初始化数据迁移和数据同步
python manage.py makemigration myLesson
python manage.py migrate
 
models数据模型:
每个应用一般都会定义一个或多个models,这个数据models实际上是与数据库相关的,models中的每个属性都是数据库当中的一个字段,每个字段都是数据库中的一个列。在models中定义的每个类相当于数据库当中的table
每个class属性斗士models中的某些字段类的实例,并且每个人字段类都有一些参数
参考文章:http://blog.csdn.net/ab198604/article/details/12655765
 
【3】创建序列化类
创建web api,第一件事就是序列化和反序列化,以便MyLesson实例可以转化为可表述的内容,例如json
 
from rest_framework import serializers
from myLesson.models import MyLesson, LANGUAGE_CHOICES, STYLE_CHOICES
 
 
class MyLessonSerializer(serializers.Serializer):
    id = serializers.IntegerField(read_only=True)
    title = serializers.CharField(required=False, allow_blank=True, max_length=100)
    code = serializers.CharField(style={'base_template': 'textarea.html'})
    linenos = serializers.BooleanField(required=False)
    language = serializers.ChoiceField(choices=LANGUAGE_CHOICES, default='python')
    style = serializers.ChoiceField(choices=STYLE_CHOICES, default='friendly')
 
    def create(self, validated_data):
        """
        Create and return a new `MyLesson` instance, given the validated data.
        """
        return MyLesson.objects.create(**validated_data)
 
    def update(self, instance, validated_data):
        """
        Update and return an existing `MyLesson` instance, given the validated data.
        """
        instance.title = validated_data.get('title', instance.title)
        instance.code = validated_data.get('code', instance.code)
        instance.linenos = validated_data.get('linenos', instance.linenos)
        instance.language = validated_data.get('language', instance.language)
        instance.style = validated_data.get('style', instance.style)
        instance.save()
        return instance

 

该序列化类的前面部分,定义了要序列化和反序列化的类型,creat和update方法定义了如何创建和修改正确的对象实例。
 
ModelSerializer类可以来快速生成序列化部分
 
class MyLessonSerializer(serializers.ModelSerializer):
    class Meta:
        model = MyLesson
        fields = ('id', 'title', 'code', 'linenos', 'language', 'style')
 
ModelSerializer类自动决定成员的属性,并有默认的create()和update()方法
 
【4】使用Serializers
python manage.py shell 进入终端交互模式
#在shell终端输入:
from myLesson.models import MyLesson
from myLesson.serializers import MyLessonSerializer
from rest_framework.renderers import JSONRenderer
from rest_framework.parsers import JSONParser
 
myLesson = Mylesson(code='foo = "bar"\n')
myLesson.save()
 
serializer = MyLessonSerializer(myLesson)
serializer.data
#此时输出的是python原生的数据类型
 
content = JSONRenderer().render(serializer.data)
content
#此时输出的Json数据类型
 
from django.utils.six import BytesIO
stream = BytesIO(content)
data = JSONParser().parse(stream)
#反序列化,转化为python原生的数据类型
 
serializer = MyLessonSerializer(data=data)
serializer.is_valid()
# True
serializer.validated_data
# OrderedDict([('title', ''), ('code', 'print "hello, world"\n'), ('linenos', False), ('language', 'python'), ('style', 'friendly')])
serializer.save()
#转换为对象实例
 
serializer = MyLessonSerializer(MyLesson.objects.all(), many=True)
serializer.data
#序列化querysets

 

【5】用Serializer写一个的Django views
 
不使用rest framework的其他特性,仅编写正常的django view
 
from django.http import HttpResponse, JsonResponse
from django.views.decorators.csrf import csrf_exempt
from rest_framework.renderers import JSONRenderer
from rest_framework.parsers import JSONParser
from myLesson.models import MyLesson
from myLesson.serializers import MyLessonSerializer
 
@csrf_exempt
def MyLesson_list(request):
    """
    List all code MyLesson, or create a new myLesson.
    """
    if request.method == 'GET':
        myLesson = MyLesson.objects.all()
        serializer = MylessonSerializer(myLesson, many=True)
        return JsonResponse(serializer.data, safe=False)
 
    elif request.method == 'POST':
        data = JSONParser().parse(request)
        serializer = MyLessonSerializer(data=data)
        if serializer.is_valid():
            serializer.save()
            return JsonResponse(serializer.data, status=201)
        return JsonResponse(serializer.errors, status=400)
 
 
@csrf_exempt
def MyLesson_detail(request, pk):
    """
    Retrieve, update or delete a code MyLesson.
    """
    try:
        myLesson = MyLesson.objects.get(pk=pk)
    except MyLesson.DoesNotExist:
        return HttpResponse(status=404)
 
    if request.method == 'GET':
        serializer = MyLessonSerializer(myLesson)
        return JsonResponse(serializer.data)
 
    elif request.method == 'PUT':
        data = JSONParser().parse(request)
        serializer = MyLessonSerializer(myLesson, data=data)
        if serializer.is_valid():
            serializer.save()
            return JsonResponse(serializer.data)
        return JsonResponse(serializer.errors, status=400)
 
    elif request.method == 'DELETE':
        myLesson.delete()
        return HttpResponse(status=204)
 
在myLesson中创建urls.py
from django.conf.urls import url
from myLesson import views
 
urlpatterns = [
    url(r'^myLesson/$', views.MyLesson_list),
    url(r'^myLesson/(?P<pk>[0-9]+)/$', views.Mylesson_detail),
]

 

在myTest的urls.py中添加
from django.conf.urls import url, include
 
urlpatterns = [
    url(r'^', include('myLesson.urls')),
]

 

测试:
http http://127.0.0.1:8000/myLesson/

转载于:https://www.cnblogs.com/jingbostar/p/6689173.html

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