[PYTHON] Hello World (beginners) on Django

Introduction

I wanted to get a feel for Python, and I used the most popular framework called Django to display Hello World in the browser, so I'll post a memorandum of it.

I referred to this article this time.

Django's first Hello World https://qiita.com/Yuji_6523/items/d601ad11ad49b9e7ab0e

As a prerequisite, python and pip are already installed.

Install django command

Run pip install django to install the django command.

$ python --version
Python 3.8.2

$ pip install django
# (abridgement)

$ python -m django --version
3.1

Create a Django project

This time, it is an example of creating a project named helloWorldProject.

You can create a project by running the command django-admin startproject [project name] [directory to create].

$ django-admin startproject helloWorldProject .
$ tree 
.
├── helloWorldProject
│   ├── __init__.py
│   ├── asgi.py
│   ├── settings.py
│   ├── urls.py
│   └── wsgi.py
└── manage.py

Add application

Since there is nothing at this point, let's add an application that starts when accessed with domain / hello and a browser.

This time we will add an application named hello. You can add an application by running the command python manage.py startapp [application name].

$ python manage.py startapp hello
$ tree
.
├── hello
│   ├── __init__.py
│   ├── admin.py
│   ├── apps.py
│   ├── migrations
│   │   └── __init__.py
│   ├── models.py
│   ├── tests.py
│   └── views.py
├── helloWorldProject
│   ├── __init__.py
│   ├── __pycache__
│   │   ├── __init__.cpython-38.pyc
│   │   └── settings.cpython-38.pyc
│   ├── asgi.py
│   ├── settings.py
│   ├── urls.py
│   └── wsgi.py
└── manage.py

Addition to settings.py

If this is left as it is, the hello application has not been applied, so add the settings.

Add that there is an application called hello in helloWorldProject / settings.py.

helloWorldProject/settings.py

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    #add to
    'hello',
]

Routing settings

Set the routing settings in helloWorldProject / urls.py.

helloWorldProject/urls.py

from django.contrib import admin
from django.urls import path, include #include added

urlpatterns = [
    path('admin/', admin.site.urls),
    #add to
    path('', include('hello.urls')),
]

You may write path ('hello', here, but this time, create a file called hello / urls.py and`` domain / hello for routing. Throw it all at hello / urls.py.

The reason for this is to aim for a program with high aggregation and low coupling as much as possible.

In addition, create a new hello / urls.py and set it to call the index () function of hello / views.py when accessed with domain / hello.

hello/urls.py(Newly added file)

from django.urls import path

from . import views

urlpatterns = [
    path('hello', views.index),
]

view settings

Create a ʻindex () function in hello / views.pyas you set inhello / urls.py`.

This time, the file of Content-Type: text / html described as Hello World is returned in the HTTP response.

hello/views.py

from django.http import HttpResponse

def index(request):
    return HttpResponse('Hello World')

migration

Although it is not so relevant this time, migration here refers to the function that automatically creates and manages the database definition used in the application.

It can be executed with the following command.

$ python manage.py migrate

If the migration is successful, there should be no error after executing the command.

Boot on localhost

You can start it on the local host with the following command.

$ python manage.py runserver

By default, it starts on port 8000, so if you access http: // localhost: 8000 / hello and see Hello World written in python: hello / views.py, it is successful. That's it.

Summary

--You can now create projects using a framework called Django --You can now add applications in Django --You can now start the application on the local host with Django and check the operation.

at the end

The project created this time has been released on GitHub.