Django rest framework官方文档示例（一）

一、序列化和反序列化

1.1 创建虚拟环境并激活

$ virtualenv tutorial
Using base prefix 'd:\\python37'
New python executable in E:\new_work\tutorial\Scripts\python.exe
Installing setuptools, pip, wheel...
done.
cd tutorial/
$ source Scripts/activate
(tutorial)
kanlgle@DESKTOP-D130RKQ MINGW64 /e/new_work/tutorial

1.2 安装django和djangorestframework

$ pip install django
$ pip install djangorestframework
$ pip install pygments #语法高亮

1.3 创建工程和app

(tutorial)
kanlgle@DESKTOP-D130RKQ MINGW64 /e/new_work/tutorial
$ django-admin startproject tutorial
kanlgle@DESKTOP-D130RKQ MINGW64 /e/new_work/tutorial
$ cd tutorial/
(tutorial)
kanlgle@DESKTOP-D130RKQ MINGW64 /e/new_work/tutorial/tutorial
$ python manage.py startapp snippets
(tutorial)

1.4 添加到INSTALLED_APPS

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'rest_framework',
    'snippets',
]

1.5 创建数据库表，迁移

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 Snippet(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',)

$ python manage.py makemigrations
$ python manage.py migrate

1.6 创建serializers.py

from rest_framework import serializers
from snippets.models import Snippet, LANGUAGE_CHOICES, STYLE_CHOICES


class SnippetSerializer(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):
        """
        根据提供的验证过的数据创建并返回一个新的`Snippet`实例。
        """
        return Snippet.objects.create(**validated_data)

    def update(self, instance, validated_data):
        """
        根据提供的验证过的数据更新和返回一个已经存在的`Snippet`实例。
        """
        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

1.7 使用序列化类

$ python manage.py shell
Python 3.7.1 (v3.7.1:260ec2c36a, Oct 20 2018, 14:57:15) [MSC v.1915 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> from snippets.models import Snippet
from snippets.serializers import SnippetSerializer
from rest_framework.renderers import JSONRenderer
from rest_fr
>>>
>>> from snippets.models import Snippet
Traceback (most recent call last):
  File "", line 1, in 
ModuleNotFoundError: No module named 'ppets'
>>> from snippets.models import Snippet
>>> from snippets.serializers import SnippetSerializer
>>> from rest_framework.renderers import JSONRenderer
>>> from rest_framework.parsers import JSONParser
>>> snippet = Snippet(code='foo = "bar"\n')
>>> snippet.save()
>>> snippet = Snippet(code='print "hello, world"\n')
>>> snippet.save()
>>> serializer = SnippetSerializer(snippet)
>>> serializer.data
{'id': 2, 'title': '', 'code': 'print "hello, world"\n', 'linenos': False, 'language': 'python', 'style': 'friendly'}
>>> content = JSONRenderer().render(serializer.data)
>>> content
b'{"id":2,"title":"","code":"print \\"hello, world\\"\\n","linenos":false,"language":"python","style":"friendly"}'

反序列化

>>> from django.utils.six import BytesIO
>>> stream = BytesIO(content)
>>> data = JSONParser().parse(stream)
>>> serializer = SnippetSerializer(data=data)
>>> serializer.is_valid()
True
>>> serializer.validated_data
OrderedDict([('title', ''), ('code', 'print "hello, world"'), ('linenos', False), ('language', 'python'), ('style', 'friendly')])
>>> serializer.save()

1.8 使用ModelSerializer，可以不用写重复的字段

class SnippetSerializer(serializers.ModelSerializer):
    class Meta:
        model = Snippet
        fields = ('id', 'title', 'code', 'linenos', 'language', 'style')

>>> from snippets.serializers import SnippetSerializer
>>> serializer = SnippetSerializer()
>>> print(repr(serializer))
查看所有字段

ModelSerializer会自动实现create和update函数

1.9 编写视图函数和urls.py

from django.http import HttpResponse
from django.views.decorators.csrf import csrf_exempt
from rest_framework.renderers import JSONRenderer
from rest_framework.parsers import JSONParser
from snippets.models import Snippet
from snippets.serializers import SnippetSerializer

class JSONResponse(HttpResponse):
    """
    An HttpResponse that renders its content into JSON.
    """
    def __init__(self, data, **kwargs):
        content = JSONRenderer().render(data)
        kwargs['content_type'] = 'application/json'
        super(JSONResponse, self).__init__(content, **kwargs)


@csrf_exempt
def snippet_list(request):
	"""
	列出所有的code snippet，或创建一个新的snippet。
	"""
	if request.method == 'GET':
		snippets = Snippet.objects.all()
		serializer = SnippetSerializer(snippets, many=True)
		return JSONResponse(serializer.data)

	elif request.method == 'POST':
		data = JSONParser().parse(request)
		serializer = SnippetSerializer(data=data)
		if serializer.is_valid():
			serializer.save()
			return JSONResponse(serializer.data, status=201)
		return JSONResponse(serializer.errors, status=400)

@csrf_exempt
def snippet_detail(request, pk):
	"""
	获取，更新或删除一个 code snippet。
	"""
	try:
		snippet = Snippet.objects.get(pk=pk)
	except Snippet.DoesNotExist:
		return HttpResponse(status=404)

	if request.method == 'GET':
		serializer = SnippetSerializer(snippet)
		return JSONResponse(serializer.data)

	elif request.method == 'PUT':
		data = JSONParser().parse(request)
		serializer = SnippetSerializer(snippet, data=data)
		if serializer.is_valid():
			serializer.save()
			return JSONResponse(serializer.data)
		return JSONResponse(serializer.errors, status=400)

	elif request.method == 'DELETE':
		snippet.delete()
		return HttpResponse(status=204)

urls.py:

项目urls
from django.conf.urls import url, include

urlpatterns = [
    url(r'^', include('snippets.urls')),
]
app的urls
from django.conf.urls import url
from snippets import views

urlpatterns = [
    url(r'^snippets/$', views.snippet_list),
    url(r'^snippets/(?P[0-9]+)/$', views.snippet_detail),
]

2.0访问