序列化与反序列化
把自定义的某个类 序列化 成基本类型 如 字段列表
创建虚拟环境
virtualenv env
source env/bin/activate
安装django
pip install django
pip install djangorestframework
pip install pygments # 我们将使用这个代码突出显示 高亮 highlighting
创建项目 和app
cd ~
django-admin.py startproject tutorial
cd tutorial
python manage.py startapp snippets
tutorial/settings.py
ALLOWED_HOSTS = ['10.8.152.31']
# Application definition
INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'snippets',
'rest_framework',
'snippets.apps.SnippetsConfig',
]
创建一个用于存储代码片段的简单代码段模型
snippets/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 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 snippets
python manage.py migrate
snippets/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):
"""
给定验证后的数据,创建并返回一个新的“片段”实例.
"""
return Snippet.objects.create(**validated_data)
def update(self, instance, validated_data):
"""
在已验证的情况下,更新并返回现有的“片段”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
python manage.py shell
序列化
from snippets.models import Snippet
from snippets.serializers import SnippetSerializer
from rest_framework.renderers import JSONRenderer json渲染器
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': u'', 'code': u'print "hello, world"\n', 'linenos': False, 'language': u'python', 'style': u'friendly'}
转为json数据
content = JSONRenderer().render(serializer.data)
content
# '{"id": 2, "title": "", "code": "print \\"hello, world\\"\\n", "linenos": false, "language": "python", "style": "friendly"}'
反序列化: 其他类型转化为python基本类型
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"\n'), ('linenos', False), ('language', 'python'), ('style', 'friendly')])
serializer.save()
# <Snippet: Snippet object>
serializer = SnippetSerializer(Snippet.objects.all(), many=True)
serializer.data
snippets/serializers.py 可以代替之前的内容
#使用下面代码替换掉SnippetSerializer类
#序列化的对象 和字段
class SnippetSerializer(serializers.ModelSerializer):
class Meta:
model = Snippet
fields = ('id', 'title', 'code', 'linenos', 'language', 'style')
python manage.py shell
from snippets.serializers import SnippetSerializer
serializer = SnippetSerializer()
print(repr(serializer))
# SnippetSerializer():
# id = IntegerField(label='ID', read_only=True)
# title = CharField(allow_blank=True, max_length=100, required=False)
# code = CharField(style={'base_template': 'textarea.html'})
# linenos = BooleanField(required=False)
# language = ChoiceField(choices=[('Clipper', 'FoxPro'), ('Cucumber', 'Gherkin'), ('RobotFramework', 'RobotFramework'), ('abap', 'ABAP'), ('ada', 'Ada')
snippets/views.py
from django.http import HttpResponse, JsonResponse
from django.views.decorators.csrf import csrf_exempt 取消身份验证的作用局部取消csrf认证
from rest_framework.renderers import JSONRenderer
from rest_framework.parsers import JSONParser
from snippets.models import Snippet
from snippets.serializers import SnippetSerializer
@csrf_exempt
def snippet_list(request):
"""
列出所有代码段,或者创建一个新的代码段
"""
if request.method == 'GET':
snippets = Snippet.objects.all()
serializer = SnippetSerializer(snippets, many=True) 结果序列化
return JsonResponse(serializer.data, safe=False)
#JsonResponse 把类似字典的数据转化为json数据
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):
"""
检索、更新或删除代码段。
"""
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)
snippets/urls.py
from django.conf.urls import url
from snippets import views
urlpatterns = [
url(r'^snippets/$', views.snippet_list),
url(r'^snippets/(?P<pk>[0-9]+)/$', views.snippet_detail),
]
tutorial/urls.py
from django.conf.urls import url,include
from django.contrib import admin
urlpatterns = [
url(r'^admin/', admin.site.urls),
url(r'^', include('snippets.urls')),
]
python manage.py makemigrations
python manage.py migrate
python manage.py createsuperuser
pip install httpie
测试 python manage.py runserver 0.0.0.0:8888
http http://10.8.152.31:8888/snippets/2/
http http://10.8.152.31:8888/snippets/