Django programming: a simple and powerful Python web programming framework

Django Programming: A simple and powerful Python Web programming framework

In the Python programming world, Django is a popular Web programming framework. The framework provides many powerful features, such as automated model mapping, automatically generated management sites, reusable application modules, etc. These features make Django one of the preferred frameworks for developers. At the same time, Django is easy to learn and does not require developers to have excessive web development experience, so it is favored by many beginners. This article will introduce you to the basic features, usage, and related advantages and disadvantages of Django.

1. Basic features of Django

(1) Django has model mapping function

One of the main features of Django is that it supports automated ORM (Object Relational Mapping) , Object-Relational Mapping) function. Simply put, Django will automatically map the data in the database into a Python object. This operation allows developers to focus more on the implementation of business logic instead of being distracted by the relationship between data.

(2) Django automatically generates an admin site

Django also provides a built-in admin site to facilitate developers to manage the data processed by the application. This admin site is automatically generated and can be easily customized by developers.

(3) Django supports reusable application modules

Django applications can be reused between different projects. These applications can be reused after following a specific directory structure. Use Django's templates and URL configuration for direct use. At the same time, Django also provides some commonly used application modules such as user authentication and website management, allowing developers to complete the development of Web applications more quickly.

2. How to use Django

(1) Install Django

Before installing Django, you need to confirm whether Python has been installed. If you have not installed Python, please go to the official website of Python:

https://www.python.org/downloads/

to download and install the Python version suitable for your computer operating system . After the installation is complete, you can start installing Django.

Installing Django is very simple, just open the command line and enter the following:

pip install django

After entering the above command, Django will automatically be installed on your computer.

(2) Create a Django project

After installing Django, you need to use the following command to create a new project:

django-admin startproject projectname

Where, projectname is the one you want to create project name. The above command will cause Django to create a project folder with a standard structure and the other files it contains.

(3) Create a Django application

After installing Django, you can use the following command to create a new application:

python manage.py startapp appname

where appname is your The name of the application you wish to create. This command will create a folder with a standard structure that contains files such as views, templates, and models for the application.

(4) Django’s model definition

Django’s ORM feature allows us to avoid writing SQL code in specific business logic. Instead, we can easily describe our database schemas through "model definitions" in Django, and Django will automatically map them to the database.

Here is an example showing how to create a simple model:

from django.db import models
 
class Blog(models.Model):
    name = models.CharField(max_length=100)
    tagline = models.TextField()
 
    def __str__(self):
        return self.name

The above code defines a model class named Blog. name and tagline are two fields, of CharField and TextField type respectively. You can add or remove fields as needed and Django will automatically change the database schema.

(5) Create a route

In Django, the framework will determine which view functions to handle the request based on the requested URL. To do this we have to define routes. Here is an example:

from django.conf.urls import url
from myapp.views import HomeView
 
urlpatterns = [
    url(r'^$', HomeView.as_view(), name='home'),
]

The above code defines a route named "home" and points it to an instance of the HomeView class. This route will be bound to the site homepage.

(6) Create a view

The view is the code block in the Web framework responsible for rendering web pages. Views in Django are class-based, which allows us to customize the view and add new methods. The following is an example:

from django.http import HttpResponse
from django.views import View
 
class HomeView(View):
    def get(self, request):
        return HttpResponse('Welcome to my homepage!')

The above code defines a class named HomeView, and the get method is used to render the requested content.

(7) Create a template

In order for the view to return renderable content, an appropriate template must be defined. Here is an example:

<!DOCTYPE html>
<html>
<head>
    <title>{{ title }}</title>
</head>
<body>
    <h1>{{ greeting }}</h1>
</body>
</html>

The above is an HTML template that contains two placeholders that can be filled in by a view and rendered onto the user interface.

3. Advantages and disadvantages of Django

Advantages:

(1) Automated ORM mapping makes the relationship between data easier to maintain.

(2) The built-in management site allows developers to quickly create and customize site management functions.

(3) The reusability of the application is good, and we can easily transplant the application to different projects.

(4) Django has a wide range of usage examples and has a large number of open source projects and community support, so developers can quickly solve various problems encountered.

shortcoming:

(1) There may be a high learning curve. Although Django provides the tools and frameworks you need, it still takes some time to learn to use these tools.

(2) Not suitable for small websites. If we need to develop a small website that is efficient, responsive, and simple to use, Django may be too complicated to use.

In this article, we explore the basic features, usage methods, and related advantages and disadvantages of the Django programming framework. Although Django may have some shortcomings, its features such as automated ORM mapping, built-in admin site, and good application reusability still make it one of the preferred frameworks for developers. At the same time, Django has a wide range of usage examples, many open source projects and community support, so developers can get help quickly.

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