Py009-01-01restful由来

1.开发模式

  • 普通开发模式(前后端放在一起写)
  • 前后端分离

2.后端开发

  • 为前端提供URL(API/接口开发）
  • 永远返回 HttpResponse

3.Django 中的 FBV/CBV

  • FBV(function base view)
  • CBV(class base view)

实践

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# step001 新建 django项目 dj_restful    
# app 名为 app001 

# step002 修改 urls.py

from app001 import views;
urlpatterns = [
    re_path(r'^users/',views.users)
]

# step003 修改 app001/views.py

import json
from django.shortcuts import render,HttpResponse

def users(request):
    user_list = ['alex','aaa','bbb'];
    return HttpResponse(json.dumps(user_list));


# step004 启动 django 项目
访问 http://localhost:8000/users/

# 返回 
["alex","aaa","bbb"]

# 这就是你的第一个接口

FBV 函数作为视图

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def users(request):
    user_list = ['alex','aaa','bbb'];
    return HttpResponse(json.dumps(user_list));

CBV 类作为视图

假如写个学生信息接口

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# 第一步 修改 urls.py
from django.urls import path,re_path
from app001 import views;

urlpatterns = [
    re_path(r'^students/', views.StudentsView.as_view())
]

# 第二步 继承 View
from django.views import  View;
class StudentsView(View):
    def get(self,request,*args,**kwargs):
        return HttpResponse('get');

    def post(self,request,*args,**kwargs):
        return HttpResponse('post');

    def put(self,request,*args,**kwargs):
        return HttpResponse('put');

    def delete(self,request,*args,**kwargs):
        return HttpResponse('delete');

# 第三步 注释掉 settings.py 里的 csrf验证

# 第四步 安装 postman 
对 http://localhost:8000/students/ 发起 get/post/put/delete请求

4.列表生成式

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class Foo:
    pass

class Bar:
    pass

v = [item() for item in [Foo,Bar]]
'''
相当于
v = [];
for i in [Foo,Bar]:
    obj = i() # 循环时Foo(), Bar() 实例对象
    v.append(obj)

v # 对象列表
'''

5.面向对象

  • 封装

    • 对同一类方法封装到类中

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      class File:
          # 文件crud方法
          def get ...
          def update ...

      class DB:
          #  sql crud方法
          def get ...
          def update ...

    • 将数据封装到对象中

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      class Student:
          def __init__(self,name,age):
              self.name = name
              self.age = age

      stu1 = Student('Alex',18)

6.封装示例

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class Request():
    def __init__(self,obj):
        self.obj = obj;

    @property
    def user(self):
        return self.obj.authticate()

class Auth():
    def __init__(self,name,age):
        self.name = name
        self.age = age
    
    def authticate(self):
        return self.name

# 接口 class
class APIView():
    # 派发事件
    def dispatch(self):
        # 利用反射   get/post/put/delete
        self.get();


    def get(self):
        a = Auth('alex',18)
        req = Request(a);
        print(req.user)

obj = APIView()
obj.dispatch(); # 返回 alex