7.2. Introduction to Django

7.2.1. Basic introduction ¶

Django is an open source Web application framework written by Python.

Using Django, Python programmers can easily complete most of the content needed by a formal website with very little code, and further develop a full-function Web service Django itself based on MVC model, that is, Model (model) + View (view) + Controller (controller) design pattern. MVC pattern simplifies subsequent modifications and extensions of the program, and makes it possible to reuse a certain part of the program.

MVC advantages:

• Low coupling

• Quick development

• Easy to deploy

• High reusability

• Low maintenance cost

• …

Python plus Django is the best combination for rapid development, design and deployment of websites.

7.2.2. Characteristics ¶

• Powerful database function

• Comes with powerful background functions.

• Elegant web site

7.2.3. MVC and MTV model ¶

7.2.4. MVC model ¶

MVC pattern (Model-view-controller) is a software architecture pattern in software engineering, which divides the software system into three basic parts: Model, View and Controller.

MVC are connected together in a plug-in, loosely coupled manner.

• Model (M)-the function of writing a program, which is responsible for mapping business objects to databases (ORM).

• View (V)-graphical interface, responsible for interaction with the user (page).

• Controller (C)-responsible for forwarding requests and processing requests.

Simple figure:

User operation flow chart:

7.2.5. MTV model ¶

The MTV mode of Django is essentially the same as that of MVC, and it is also for the purpose of maintaining a loosely coupled relationship between components, except that the definition is slightly different. The MTV of Django refers to:

• M representation model (Model): the function of writing a program, which is responsible for mapping business objects to databases (ORM).

• T represents template (Template): responsible for how to display the page (html) to the user.

• V represents the view (View): responsible for the business logic and calling Model and Template when appropriate.

In addition to the above three layers, you also need a URL dispatcher, which is used to distribute URL page requests to different View processing. The response mode of View calling the corresponding Model and Template,MTV is as follows:

Simple figure:

User operation flow chart:

解析：

The user initiates a request (request) to our server through the browser, which accesses the view function:

• a.如果不涉及到数据调用，那么这个时候视图函数直接返回一个模板也就是一个网页给用户。

• b.如果涉及到数据调用，那么视图函数调用模型，模型去数据库查找数据，然后逐级返回。

The view function fills the returned data into the spaces in the template and finally returns the web page to the user.

Reference address:

[1] Https://www.cnblogs.com/liuhui0308/p/12189658.html