准备工作
一丶配置虚拟环境
1.安装虚拟包:pip install virtualenv
2.创建一个用于虚拟环境的目录,并进入到目录下
3.执行 python -m venv 虚拟环境名
4.执行 virtualenv 虚拟环境名
5.在目录下激活虚拟环境
windos下:source env\Scripts\activate
linux下:source env/bin/activate
6.停止虚拟环境 deactivate指令或者关闭终端
二丶用于代码高亮显示pip install pygments
开始
一丶创建一个项目
1.新建一个项目目录,在目录中创建一个Django项目
cd 项目目标目录 django-admin.py startproject 项目名 cd 项目目录下
2.创建一个Django应用
python manage.py startapp snippets
3.将rest_framework和新建的应用注册到settings.py的INSTALLED_APPS中
INSTALLED_APPS = (
...
'rest_framework',
'snippets.apps.SnippetsConfig',
)
二丶编辑模型层
1.编辑模型层文件
应用下的models.py文件
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',)
2.迁移数据
项目根目录下 python manage.py makemigrations 应用名 python manage.py migrate
三丶序列化
1.应用下建立serializers.py文件
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):
"""
Create and return a new `Snippet` instance, given the validated data.
"""
return Snippet.objects.create(**validated_data)
def update(self, instance, validated_data):
"""
Update and return an existing `Snippet` 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
四丶使用序列化器
一丶序列化
1.进入python shell:python manage.py shell
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()
2.查看实例化的数据
serializer = SnippetSerializer(snippet) serializer.data
# {'id': 2, 'title': u'', 'code': u'print "hello, world"\n', 'linenos': False, 'language': u'python', 'style': u'friendly'}3.转换为json数据
content = JSONRenderer().render(serializer.data)
content
# '{"id": 2, "title": "", "code": "print \\"hello, world\\"\\n", "linenos": false, "language": "python", "style": "friendly"}'
二丶反序列化
1.解析字符串为python原生的数据类型
from django.utils.six import BytesIO stream = BytesIO(content) data = JSONParser().parse(stream)
2.将原生数据类型变为对象实例
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>
3.序列化querysets实例,将many=True参数加入序列化器
serializer = SnippetSerializer(Snippet.objects.all(), many=True)
serializer.data
# [OrderedDict([('id', 1), ('title', u''), ('code', u'foo = "bar"\n'), ('linenos', False), ('language', 'python'), ('style', 'friendly')]), OrderedDict([('id', 2), ('title', u''), ('code', u'print "hello, world"\n'), ('linenos', False), ('language', 'python'), ('style', 'friendly')]), OrderedDict([('id', 3), ('title', u''), ('code', u'print "hello, world"'), ('linenos', False), ('language', 'python'), ('style', 'friendly')])]
五丶使用ModelSerializers
REST framework包括Serializer类和ModelSerializer类,这样可以使代码更加的整洁.
ModelSerializer就像是Django的表单,不会有特别的功能但是是序列化的一个快捷方式.
1.找到应用下的serializers.py文件,替换代码
class SnippetSerializer(serializers.ModelSerializer):
class Meta:
model = Snippet
fields = ('id', 'title', 'code', 'linenos', 'language', 'style')
2.查看序列化器的所有字段
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')...
# style = ChoiceField(choices=[('autumn', 'autumn'), ('borland', 'borland'), ('bw', 'bw'), ('colorful', 'colorful')...
六丶编写序列化试图
1.编辑应用下的views.py文件
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 snippets.models import Snippet
from snippets.serializers import SnippetSerializer2.加入以下方法
@csrf_exempt
def snippet_list(request):
"""
List all code snippets, or create a new snippet.
"""
if request.method == 'GET':
snippets = Snippet.objects.all()
serializer = SnippetSerializer(snippets, many=True)
return JsonResponse(serializer.data, safe=False)
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)
3.上述代码的升级版,用于增删改查数据
@csrf_exempt #跨越csrf令牌,进行POST请求
def snippet_detail(request, pk):
"""
Retrieve, update or delete a 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)
4.url设置
创建应用的urls.py文件
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),
]项目的urls.py文件
from django.conf.urls import url, include
urlpatterns = [
url(r'^', include('snippets.urls')),
]
七丶测试Web API
1.运行Django服务:python manage.py runserver
2.安装httpie:pip install httpie,这是一个http客户端用python编写对客户非常友好
3.得到所有的数据列表
http http://127.0.0.1:8000/snippets/
HTTP/1.1 200 OK
...
[
{
"id": 1,
"title": "",
"code": "foo = \"bar\"\n",
"linenos": false,
"language": "python",
"style": "friendly"
},
{
"id": 2,
"title": "",
"code": "print \"hello, world\"\n",
"linenos": false,
"language": "python",
"style": "friendly"
}
]
4.通过id得到列表
http http://127.0.0.1:8000/snippets/2/
HTTP/1.1 200 OK
...
{
"id": 2,
"title": "",
"code": "print \"hello, world\"\n",
"linenos": false,
"language": "python",
"style": "friendly"
}
5.也可以通过浏览器来访问Django项目
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