Samuli Natri - Django - The Easy Way (3rd Edition)

Visit http://www.python.org and install Python. Check Add Python x to PATH if you are using the Windows installer.

Search for Terminal or Command Prompt to find a terminal program and open it up.

Run the following command:

Command Prompt

You might need to use py or python on your system. This puts the Python interpreter in interactive mode:

Command Prompt

Make sure you are running Python version 3.

Python interpreter is a program that translates source code into intermediate representation and immediately executes it.

In the interactive prompt we can type and run Python code directly without creating a .py file:

Interactive Prompt

This chapter covers

• Creating virtual environments
• Installing Django
• Creating a new Django project

With virtual environments each project can have its own unique set of dependencies. You can work on multiple projects simultaneously without them interfering with each other.

Use these commands to create and activate a virtual environment in Unix-like systems:

Command Prompt

Use these commands in Windows:

Command Prompt

You can create the virtual environment directory anywhere in your system. In this case we use the .virtualenvs directory inside the users home directory.

The (mysite) prefix indicates that the environment is active:

Command Prompt

deactivate command deactivates the environment.

Check out virtualenvwrapper and pyenv if you are looking for more comprehensive tools for virtual environment and Python version management.

Django is installed like any other Python package:

Command Prompt

This will install Django inside the virtual environment directory we just created (~/.virtualenvs/mysite). Pip is a Python package manager.

Create a new Django project:

Command Prompt

• django-admin is a command line tool for administrative tasks.
• The startproject command creates the Django project directory structure. mysite is the name of the project. Use . (dot) to create the project in the current directory.

You should now have this kind of directory structure:

Command Prompt

You have to tell Django which settings youre using by defining an environment variable named DJANGO_SETTINGS_MODULE. manage.py works like the django-admin utility but it also conveniently points the DJANGO_SETTINGS_MODULE system variable to the project settings.py file.

We use the term project to describe a Django web application. The mysite subdirectory inside the main mysite directory is the project Python package. Inside it we have the project settings, URL declarations and WSGI configuration. The __init__.py file makes this directory a Python package.

WSGI is a standard that defines how applications and servers communicate with each other.

Django provides a built-in development server. Run the following command to start it:

Command Prompt

The You have x unapplied migration(s) warning is related to database migrations. You can ignore it for now.

Visit http://127.0.0.1:8000 with a browser and you should see the welcome screen:

Use the built-in server only for development purposes. There are better options for production environments (like Nginx and Gunicorn).

We use virtual environments to manage project dependencies. Pip package manager makes it easy to install Python packages (like Django). The django-admin startproject mysite . command creates a Django directory structure. Django comes with a lightweight web server that you can use when building the website.