Adventures in Machine Learning

Your Guide to Creating a Django To-Do App: From Setup to Views

Title: A Beginner’s Guide to Setting Up a Django To-Do AppDjango is a powerful web framework that has been steadily gaining popularity among developers. In this article, we will explore how to set up a virtual environment, create a project directory, and install and test Django.

We will then move on to creating a simple to-do app using Django. Whether you are a beginner or an experienced developer, this article will provide you with a comprehensive overview of how to get started with Django.

1) Setting Up Virtual Environment and Django

Creating a Virtual Environment and Project Directory

Before we start working with Django, it is essential to create a virtual environment and project directory. A virtual environment is an isolated Python environment that allows us to install packages and dependencies for our project without affecting the system’s Python installation.

Here’s how you can create a virtual environment and project directory:

1. Open a terminal window or command prompt and navigate to the directory where you want to create the project directory.

2. Type the following command to create a virtual environment:

`python -m venv env`

This command will create a new folder named ‘env’, which will contain a copy of Python and pip, the package manager.

3. Activate the virtual environment by typing the following command:

`source env/bin/activate`

This command will activate the virtual environment, and you’ll see the name of the virtual environment in the command prompt.

4. Create a new project directory by typing the following command:

`mkdir todo_project`

This command will create a new folder named ‘todo_project’, which will be the parent directory for our Django app.

Installing and Testing Django

After creating the virtual environment and project directory, we can proceed to install Django and test it. Here’s how you can install and test Django:

1.

Make sure that your virtual environment is activated. 2.

Install Django by typing the following command:

`pip install Django`

This command will install the latest version of Django. 3.

Create a new Django project by typing the following command:

`django-admin startproject todo_project`

This command will create a new Django project with the name ‘todo_project.’

4. Test Django by navigating to the project directory (todo_project) and running the following command:

`python manage.py runserver`

This command will start the development server, and you’ll be able to see the Django welcome page by navigating to http://127.0.0.1:8000/ in your web browser.

2) Creating Django To-Do App

Scaffold the Parent Project

Now that we have set up our environment and installed Django, we can start working on our To-Do App. Here’s how you can scaffold the parent project:

1.

Create a new Django app inside the parent project by typing the following command:

`python manage.py startapp todo_app`

This command will create a new folder named ‘todo_app’, which will contain the code for our To-Do App. 2.

Register the new app by adding it to the INSTALLED_APPS list in the settings.py file located in the parent project directory. “`

# todo_project/settings.py

INSTALLED_APPS = [

‘django.contrib.admin’,

‘django.contrib.auth’,

‘django.contrib.contenttypes’,

‘django.contrib.sessions’,

‘django.contrib.messages’,

‘django.contrib.staticfiles’,

‘todo_app’,

]

… “`

3.

Create a new Django model by editing the models.py file located in the todo_app directory. “`

# todo_app/models.py

from django.db import models

class Task(models.Model):

title = models.CharField(max_length=200)

description = models.TextField()

completed = models.BooleanField(default=False)

def __str__(self):

return self.title

“`

4.

Create a migration by running the following command:

`python manage.py makemigrations`

This command will generate a new migration file that defines how to create the Task model in the database. 5.

Apply the migration by running the following command:

`python manage.py migrate`

This command will create the table for the Task model in the database.

Get Started on To-Do List App

We’ve now created the necessary components for our To-Do App. Let’s start adding functionality by creating views, URLs, and templates.

Here’s how you can get started:

1. Create a new Django view by editing the views.py file located in the todo_app directory.

“`

# todo_app/views.py

from django.shortcuts import render

from .models import Task

def index(request):

tasks = Task.objects.all()

return render(request, ‘index.html’, {‘tasks’: tasks})

“`

2. Create a new URL pattern by editing the urls.py file located in the todo_app directory.

“`

# todo_app/urls.py

from django.urls import path

from .views import index

urlpatterns = [

path(”, index, name=’index’),

]

“`

3. Create a new Django template by creating a new file named ‘index.html’ in the todo_app/templates/ directory.

“`

To-Do App

To-Do List

    {% for task in tasks %}

  • {{ task.title }}
  • {% endfor %}

“`

4. Test the To-Do App by running the development server using the following command:

`python manage.py runserver`

Navigate to http://127.0.0.1:8000/ in your web browser, and you should see the title ‘To-Do App’ and an unordered list containing your tasks.

Conclusion

In this article, we learned how to set up a virtual environment, create a project directory, install and test Django, and create a simple to-do app using Django. We covered essential topics such as creating a new Django project, registering a new Django app, creating models and migrations, creating views, URLs, and templates.

By following the steps outlined in this article, you should now have a better understanding of how Django works and how to create a simple web app using Django.

3) Designing To-Do Data

Defining Data Models

Now that we have created a parent project and a new app with a model for our To-Do App, it’s time to define our data models. A data model is a way to organize and structure our data to ensure that it’s consistent and easy to work with.

Here’s how you can define your data models:

1. Edit the models.py file located in the todo_app directory, and define the properties of our Task model.

“`

# todo_app/models.py

from django.db import models

class Task(models.Model):

title = models.CharField(max_length=200)

description = models.TextField()

completed = models.BooleanField(default=False)

def __str__(self):

return self.title

“`

In this example, we have created a Task model that has a title (CharField with max length 200), a description (TextField), and a completed flag (BooleanField with a default value of False). The `__str__()` method is also defined, which returns the title of the task when it’s printed to the console.

2. Run the following command to create a new migration:

`python manage.py makemigrations`

This command will generate a new migration based on the changes made to the models.

Creating the Database

Now that we have defined our data models, we need to create the database. Django provides a useful command-line tool called `migrate` that creates and applies database migrations.

Here’s how you can create the database:

1. Run the following command to apply the migration:

`python manage.py migrate`

This command will create the necessary tables in the database based on our data models.

2. Verify that the database has been created by using a database management tool or the Django Shell (`python manage.py shell`).

“`

>>> from todo_app.models import Task

>>> Task.objects.all()

“`

This code snippet checks whether the `Task` model has been created in the database by retrieving all the `Task` objects. Since there are no objects yet, the output is an empty QuerySet.

4) Adding Sample To-Do Data

Meeting the Django Admin Interface

The Django Admin Interface is a powerful tool that allows us to interact with our data and manage our app. It comes built-in with Django and is automatically generated based on our data models.

Here’s how you can access the Django Admin Interface:

1. Create a new superuser by running the following command:

`python manage.py createsuperuser`

This command will prompt you to enter a username, email, and password for the superuser account.

2. Run the development server using the following command:

`python manage.py runserver`

Navigate to http://localhost:8000/admin/ in your web browser, and you should see the Django Admin Login page.

3. Log in to the Django Admin Interface using the superuser account you created in step 1.

Starting a To-Do List

Now that we have access to the Django Admin Interface, we can start adding sample data to our To-Do App. Here’s how you can get started:

1.

Click on the “Tasks” link on the main admin page to create a new task. 2.

Enter a title, description, and check the “completed” box if the task is complete. 3.

Click on the “Save” button to create the new task. 4.

Repeat steps 1-3 to add more tasks. 5.

Navigate to the main To-Do app page (http://localhost:8000/) to see your tasks listed. “`

To-Do App

To-Do List

    {% for task in tasks %}

  • {{ task.title }}{% if task.completed %} (completed){% endif %}
  • {% endfor %}

“`

This code snippet lists all the tasks created in the Django Admin Interface and includes a completed flag that displays next to the task title if the task is complete.

6. Test the To-Do App by running the development server using the following command:

`python manage.py runserver`

Navigate to http://localhost:8000/ in your web browser, and you should see a simple to-do list containing your sample tasks.

Conclusion

In this article, we learned how to define data models and create a database for our To-Do App using Django. We also explored how to access the Django Admin Interface and add sample data to our app.

By following the steps outlined in this article, you can now create, manage and display tasks in your To-Do App.

5) Creating Django Views

Coding First View

Now that we have our data models defined and our database created, it’s time to create views that will display our To-Do items. A view is a Python function that takes a web request and returns a web response.

Here’s how you can create your first view:

1. Create a new file called `views.py` in the `todo_app` directory.

2. Import the necessary modules:

“`

# todo_app/views.py

from django.shortcuts import render

from todo_app.models import Task

“`

3.

Define a view function to retrieve all the Task objects and render them using a template:

“`

# todo_app/views.py

def task_list(request):

tasks = Task.objects.all()

return render(request, ‘task_list.html’, {‘tasks’: tasks})

“`

Understanding Templates

A template is a text file that defines the structure and layout of a web page. Django uses its own templating system that allows us to integrate dynamic content into our pages.

Here’s how you can create a template file:

1. Create a new directory called `templates` in the `todo_app` directory.

2. Create a new file called `base.html` in the `templates` directory.

3. Define the basic structure for the base template:

“`

{% block title %}{% endblock %}

{% block content %}

{% endblock %}

“`

This base template includes two blocks, one for the title and one for the content.

Creating a Base Template

A base template serves as a template that other templates can extend from. Here’s how you can create a base template for our To-Do App:

1.

Edit the `base.html` template to include navigation links:

“`

{% block title %}{% endblock %}

{% block content %}

{% endblock %}

“`

2. Create a new file called `task_list.html` in the `templates` directory.

3. Extend the `base.html` template in `task_list.html`:

“`

{% extends ‘base.html’ %}

{% block title %}Task List{% endblock %}

{% block content %}

Task List

    {% for task in tasks %}

  • {{ task.title }}
  • {% endfor %}

{% endblock %}

“`

This template extends the `base.html` template and adds a title and content block for the task list.

Adding a Home Page Template

Now that we have a base template and a template for the task list, we can create a home page for our To-Do App. Here’s how you can create a home page template:

1.

Create a new file called `home.html` in the `templates` directory. 2.

Extend the `base.html` template in `home.html`:

“`

{% extends ‘base.html’ %}

{% block title %}Home{% endblock %}

{% block content %}

Welcome to the To-Do App!

{% endblock %}

“`

3. Create a new view function in `views.py` to render the `home.html` template:

“`

# todo_app/views.py

def home(request):

return render(request, ‘home.html’)

“`

4.

Define a URL pattern for the home page in `urls.py`:

“`

# todo_app/urls.py

from django.urls import path

from .views import task_list, home

urlpatterns = [

path(”, home, name=’home’),

path(‘tasks/’, task_list, name=’task_list’),

]

“`

Building a Request Handler

A request handler is a Python class that handles HTTP requests and returns an HTTP response. Django provides a set of class-based views that can be used to handle common web application tasks.

Here’s how you can create a request handler for our To-Do App:

1. Create a new file called `views.py` in the `todo_app` directory.

2. Import the necessary modules:

“`

# todo_app/views.py

from django.views.generic import ListView

from todo_app.models import Task

“`

3.

Create a new class called `TaskListView` that subclasses `ListView`:

“`

# todo_app/views.py

class TaskListView(ListView):

model = Task

template_name = ‘task_list.html’

context_object_name = ‘tasks’

“`

This class-based view retrieves all the `Task` objects, uses a template file named `task_list.html`, and specifies a context variable name of `tasks`. 4.

Define a URL pattern for the class-based view in `urls.py`:

“`

# todo_app/