Django Introduction: Building Web Applications with Python

Installation and Setup

Before we dive into Django, let's make sure you have it installed on your machine. Open your terminal and type the following command:

pip install Django

Once Django is installed, you can verify the installation by running:

django-admin --version

If everything is set up correctly, you should see the version number displayed.

Creating a Django Project

To create a new Django project, navigate to the desired directory in your terminal and run the following command:

django-admin startproject myproject

This command will create a new directory called "myproject" with the basic structure for your Django project.

Building a Simple Django App

Now let's create a simple Django app within our project. Move into the project directory by running:

cd myproject

Next, execute the following command to create a new app:

python manage.py startapp myapp

This will generate a new directory called "myapp" inside your project, containing the necessary files and folders for the app.

Defining Models

Models in Django represent the structure and behavior of your data. Open the models.py file inside the "myapp" directory and define a simple model, for example, a Person model:

from django.db import models

class Person(models.Model):
    name = models.CharField(max_length=100)
    age = models.IntegerField()
    

In this example, we've defined a Person model with two fields: name and age. Django provides various field types like CharField, IntegerField, DateField, and many more to handle different data types.

Creating Database Tables

To create the necessary database tables based on our models, run the following command:

python manage.py makemigrations

python manage.py migrate

The makemigrations command creates migration files based on the changes in your models, while the migrate command applies those changes to the database.

Views and Templates

Views in Django handle the business logic of your application and interact with models and templates. Open the views.py file inside the "myapp" directory and define a simple view:

from django.shortcuts import render
from .models import Person

def person_list(request):
    people = Person.objects.all()
    return render(request, 'myapp/person_list.html', {'people': people})
    

In this example, we retrieve all the Person objects from the database and pass them to the person_list.html template.