利用Django实现RESTful API
RESTful API现在很流行，这里是它的介绍 理解RESTful架构和 RESTful API设计指南.按照Django的常规方法当然也可以实现REST，但有一种更快捷、强大的方法，那就是 Django REST framework.它是python的一个模块，通过在Django里面配置就可以把app的models中的各个表实现RESTful API。下面是实现方法：
一、安装配置
pip install djangorestframework pip install markdown # Markdown support for the browsable API.pip install django-filter # Filtering support
再到Django的 settings.py 中的INSTALLED_APPS添加 rest_framework，如下：
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INSTALLED_APPS
=
(
...
'rest_framework'
,
)
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在根目录的 url.py 文件中为rest_framework框架的 login 和 logout 视图添加url：
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urlpatterns
=
[
...
url(r
'^api-auth/'
, include(
'rest_framework.urls'
, namespace
=
'rest_framework'
))
]
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二、创建model和Serializer
创建app，名为 snippets.。在视图 models.py 中添加一张表如下：
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from
django.db
import
modelsfrom pygments.lexers
import
get_all_lexers
# 一个实现代码高亮的模块
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])
# 得到所有编程语言的选项
STYLE_CHOICES
=
sorted
((item, item)
for
item
in
get_all_styles())
# 列出所有配色风格
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'
,)
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然后开始同步到数据库中：
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.
/
manage.py makemigrations snippets
.
/
manage.py migrate
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接下来需要做的就是创建 Serializer 类，类似于 Form。它的作用就是从你传入的参数中提取出你需要的数据，并把它转化为 json 格式(注意，已经是字节码了),同时支持反序列化到model对象。在 snippets 文件夹中添加 serializers.py 并在其添加如下：
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from
rest_framework
import
serializersfrom snippets.models
import
Snippet, LANGUAGE_CHOICES, STYLE_CHOICES
class
SnippetSerializer(serializers.Serializer):
# 它序列化的方式很类似于Django的forms
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'
})
# style的设置等同于Django的
widget
=
widgets.Textarea
linenos
=
serializers.BooleanField(required
=
False
)
# 用于对浏览器的上的显示
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
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三、使用Serializer
先使用 ./manage.py shell 进入Django的shell中。操作如下：
可以看到 Serializer 的使用如同 Django 的 forms.它的反序列化如下：
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from
django.utils.six
import
BytesIO
stream
=
BytesIO(content)
data
=
JSONParser().parse(stream)
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这是再把得到的数据转化为实例：
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serializer
=
SnippetSerializer(data
=
data)
serializer.is_valid()
# 开始验证
# Trueserializer.validated_data
# OrderedDict([('title', ''), ('code', 'print "hello, world"\n'), ('linenos', False), ('language', 'python'), ('style', 'friendly')])serializer.save()
# <Snippet: Snippet object>
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同时，我们还可以对 querysets 进行序列化，只需简单地在设置参数 many=True，如下：
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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')])
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四、使用 ModelSerializer
ModelSerializer类似于Django的 modelform， 可以直接关联到models中的表。如下：
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class
SnippetSerializer(serializers.ModelSerializer):
class
Meta:
model
=
Snippet
fields
=
(
'id'
,
'title'
,
'code'
,
'linenos'
,
'language'
,
'style'
)
|
五、在Django的视图中使用Serializer
首先，可以像常规Django视图的写法一样写，返回序列化的输出数据。
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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
SnippetSerializer
@csrf_exemptdef
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
)
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也可以写一个视图对应其models中的表，实现对它的删、改、查。
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@csrf_exemptdef
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
)
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添加对应的url, snippets/urls.py 中设置如下：
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from
django.conf.urls
import
urlfrom snippets
import
views
urlpatterns
=
[
url(r
'^snippets/$'
, views.snippet_list),
url(r
'^snippets/(?P<pk>[0-9]+)/$'
, views.snippet_detail),
]
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最后还要在根目录的 url.py 中添加对应的映射。
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urlpatterns
=
[
...
url(r
'^'
, include(
'snippets.urls'
)),
]
|
这时，所有的配置已经完成了。接下来就是测试我们的API
六、测试API
为了方便我们可以使用 httpie 模块来测试，启动Django，再在客户端输入 http://127.0.0.1:8000/snippets/,操作如下：
还可以进行 put 操作，修改对应的内容
本文转自 sjfbjs 51CTO博客，原文链接:http://blog.51cto.com/11886896/2064575
