宜配屋

在这个例子中，我们将使用Django编写饿了么高校外卖商家查询API接口，并且使用AJAX技术来实现API接口的使用，包括使用ajax get方法加载更多数据，使用ajax方法来更新、修改、新增、删除数据。利用API可以做到前后端分离，为开发web应用提供了便利。

安装rest framework

首先使用Pycharm新建一个Django项目，并且使用virtualenv或者pipenv虚拟环境

创建成功会自动安装Django2.1和所需依赖，restframework框架需要自己手动安装

//激活虚拟环境安装以下
(venv)$ pip install djangorestframework
(venv)$ pip install django-filter 
(venv)$ pip install pytest
(venv)$ pip install pytest-django 
//由于笔者使用Postgresql数据库，所以还需要安装以下
(venv)$ pip install psycopg2
//使用mysql数据库安装如下
(venv)$ pip install pymysql

准备数据来提供服务

数据来源：饿了么爬虫

数据内容：全国所有大学附近的外卖商家Top20

数据需要导入数据库

Django编写rest api接口

项目结构

settings.py.

// 安装的app如下
INSTALLED_APPS = [
 #...
 'rest_framework',
 'django_filters',
 'api.apps.ApiConfig',
 'front.apps.FrontConfig',
]
//restframework 配置如下
REST_FRAMEWORK = {
//这里配置了分页处理，每页最多20个项目
'DEFAULT_PAGINATION_CLASS':'api.custompagination.LimitOffsetPaginationWithUpperBound',
 'PAGE_SIZE': 20,
 'DEFAULT_FILTER_BACKENDS': (
 //这里配置了排序、过滤、搜索器
 'django_filters.rest_framework.DjangoFilterBackend',
 'rest_framework.filters.OrderingFilter',
 'rest_framework.filters.SearchFilter',
 ),
 //这里配置了用户认证，管理员才可以更改内容，未登录不能更改
 'DEFAULT_AUTHENTICATION_CLASSES':(
 'rest_framework.authentication.BasicAuthentication',
 'rest_framework.authentication.SessionAuthentication',
 ),
 //这里配置了访问次数限制，过多会返回429错误 too many requests
 'DEFAULT_THROTTLE_CLASSES': (
 'rest_framework.throttling.AnonRateThrottle',
 'rest_framework.throttling.UserRateThrottle',
 ),
 //这里配置了访问次数，anon代表匿名用户，user代表已登录用户，entries是我自己设置的作用域，300/hour代表最多300次每小时
 'DEFAULT_THROTTLE_RATES': {
 'anon': '300/hour',
 'user': '100/hour',
 'entries': '200/hour',
 },
 'DEFAULT_VERSIONING_CLASS':'rest_framework.versioning.NamespaceVersioning',
}

models.py.

from django.db import models
class Entry(models.Model):
 city = models.CharField(max_length=50)
 school = models.CharField(max_length=100)
 link = models.CharField(max_length=100,null=True,default='null')
 name = models.CharField(max_length=200)
 lat = models.CharField(max_length=20,null=True,default='0.0')
 lng = models.CharField(max_length=20,null=True,default='0.0')
 address = models.CharField(max_length=200,null=True,default='null')
 distance = models.CharField(max_length=20,null=True,default='0')
 time = models.CharField(max_length=20,null=True,default='0:00')
 contact = models.CharField(max_length=200,null=True,default='null')
 score = models.CharField(max_length=10,null=True,default='0')
 comments = models.CharField(max_length=20,null=True,default='0')
 sell = models.CharField(max_length=20,null=True,default='0')
 image = models.CharField(max_length=200,null=True,default='null')
 owner = models.ForeignKey('auth.User',related_name='entries',on_delete=models.CASCADE)
 # class Meta:
 # ordering = ('name',)
 def __str__(self):
 return self.name

serializers.py.

from rest_framework import serializers
from api.models import Entry
//这里继承自超链接模型序列器，用于把数据转换为json格式，并且显示链接
class EntrySerializer(serializers.HyperlinkedModelSerializer):
 owner = serializers.ReadOnlyField(source='owner.username')
 class Meta:
 model = Entry
 fields = ('url','pk','name','city','school','link','lat','lng','address','distance','time','contact',
 'score','comments','sell','image','owner')

views.py.

from rest_framework import generics
from rest_framework.response import Response
from rest_framework.reverse import reverse
from api.models import Entry
from api.serializers import EntrySerializer
from rest_framework import permissions
from rest_framework.permissions import IsAuthenticated
from rest_framework.throttling import ScopedRateThrottle
from api import custompermission
//这里是获取所有数据，可实现HTTP get、Post、Option操作
class EntryList(generics.ListCreateAPIView):
 //限流自定义作用域
 throttle_scope = 'entries'
 throttle_classes = (ScopedRateThrottle,)
 queryset = Entry.objects.all()
 serializer_class = EntrySerializer
 name = 'entry-list'
 filter_fields = ('city','school','name')
 search_fields = ('school','city')
 ordering_fields = ('city')

 //管理员才能post操作创建新的数据
 permission_classes = (
 permissions.IsAuthenticatedOrReadOnly,
 custompermission.IsCurrentUserOwnerOrReadOnly,
 )
 def perform_create(self, serializer):
 serializer.save(owner=self.request.user)

//这里是获取具体某一项的数据，可实现HTTP GET、PUT、PATCH、Option操作
class EntryDetail(generics.RetrieveUpdateDestroyAPIView):
 throttle_scope = 'entries'
 throttle_classes = (ScopedRateThrottle,)
 queryset = Entry.objects.all()
 serializer_class = EntrySerializer
 name = 'entry-detail'
 permission_classes = (
 permissions.IsAuthenticatedOrReadOnly,
 custompermission.IsCurrentUserOwnerOrReadOnly,
 )
//api根目录
class ApiRoot(generics.GenericAPIView):
 name = 'api-root'
 def get(self, request, *args, **kwargs):
 return Response({
 'entries': reverse(EntryList.name, request=request),
 })

urls.py.

from django.urls import path
from api import views
urlpatterns = [
 path('entries/', views.EntryList.as_view(), name=views.EntryList.name),
 path('entry-detail/<int:pk>', views.EntryDetail.as_view(), name=views.EntryDetail.name),
 path('', views.ApiRoot.as_view(), name=views.ApiRoot.name)
]

ele/urls.py.

from django.urls import path,include
urlpatterns = [
 path('v1/',include('api.urls')),
 path('v1/api-auth/',include('rest_framework.urls')),
 path('',include('front.urls'))
]

以下为启动界面

到此为止非常简单的api就写完了，接下来就是自动化测试是否达到预期效果。如图，测试通过！

在程序中调用刚刚写好的api

创建一个新的app并且添加到settings.py里面

(venv)$ python manage.py startapp front

做好的效果如下：点击加载更多会触发ajax

由于篇幅有限，这里贴出js代码使用ajax get请求刚刚写好的api接口并且添加到表格中

myjs.js.

$('#load-more').click(function () {
 $.ajax({
 method:'GET',
 url:api_url,
 dataType:'json',
 success:function (data) {
 api_url = data['next'];
 if (api_url == null){
 $('#load-more').val('已加载全部');
 $('#load-more').attr('disabled',true);
 //api_url这里就是刚刚写好的api接口
 api_url = 'v1/entries/';
 }
 var results = data['results'];
 for (i=0;i<results.length;i++){
 $('#ele-table-body').append(
 ' <tr>\n' +
 ' <th scope="col">'+results[i]['pk']+'</th>\n' +
 ' <th scope="col">'+results[i]['city']+'</th>\n' +
 ' <th scope="col"><a href="/detail/' + results[i]['pk'] +'" rel="external nofollow" >' + results[i]['name'] + '</a></th>\n' +
 ' <th scope="col">'+results[i]['school']+'</th>\n' +
 ' <th scope="col">'+results[i]['score']+'</th>\n' +
 ' </tr>'
 )
 }
 }
 })
 });

可以修改具体的一条数据，使用ajax patch方法提交数据。注：PUT方法是修改所有数据，而PATCH方法是修改局部数据

myjs.js.

 $('#edit-confirm-btn').click(function () {
 var name = $('#name').val();
 var distance = $('#distance').val();
 var adderss = $('#address').val();
 var time = $('#time').val();
 var score = $('#score').val();
 var comments = $('#comments').val();
 var sell = $('#sell').val();
 var pk = $('#pk').val();
 $.ajax({
 type:'PATCH',
 url:'/detail/' + pk,
 data:{
 "name": name,
 "distance": distance,
 "address": adderss,
 "time": time,
 "score": score,
 "comments": comments,
 "sell": sell,
 },
 success:function (data) {
 if (data.status == 'ok'){
 console.log('success');
 location.reload();
 }
 }
 })
 })

本文通过一个小例子介绍了如何使用Django调用自己写的api

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持【听图阁-专注于Python设计】。