This chapter covers how to properly configure your computer to work on Django projects. We start with an overview of the command line and use it to install the latest versions of both Django (2.0) and Python (3.6x). Then we discuss virtual environments, git, and working with a text editor.

By the end of this chapter you’ll be ready to create and modify new Django projects in just a few keystrokes.

The Command Line

The command line is a powerful, text-only view of your computer. As developers we will use it extensively throughout this book to install and configure each Django project.

On a Mac, the command line is found in a program called Terminal located at /Applications/Utilities. To find it, open a new Finder window, open the Applications folder, scroll down to open the Utilities folder, and double-click the application called Terminal.

Finder Terminal app

On Windows, there is a built-in command line program but it is difficult to use. I recommend instead using Babun, a free and open-source command line program.

Babun homepage

Click on the “Download now” button on its website, double-click it to install Babun, and upon completion drag the installer to the Recycle Bin. To use Babun go to the Start menu, select Programs, and click on Babun.

Going forward when the book refers to the “command line” it means to open a new console on your computer using either Terminal or Babun.

While there are many possible commands we can use, in practice there are six used most frequently in Django development.

  • cd (change down a directory)
  • cd .. (change up a directory)
  • ls (list files in your current directory)
  • pwd (print working directory)
  • mkdir (make directory)
  • touch (create a new file)

Open your command line and try them out. The $ dollar sign is our command line prompt: all commands in this book are intended to be typed after the $ prompt.

For example, let’s change into our Desktop directory.

$ cd ~/Desktop

Note that our current location ~/Desktop is automatically added before our command line prompt. To confirm we’re in the proper location we can use pwd which will print out the path of our current directory.

~/Desktop $ pwd
/Users/wsv/desktop

On my Mac computer this shows that I’m using the user wsv and on the desktop for that account.

Let’s create a new directory folder with mk_dir, cd into it, and add a new file index.html.

~/Desktop $ mkdir new_folder
~/Desktop $ cd new_folder
~/Desktop/new_folder $ touch index.html

Now use ls to list all current files in our directory. You’ll see there’s just the newly created index.html.

~/Desktop/new_folder $ ls
index.html

As a final step return to the Desktop directory with cd .. and use pwd to confirm the location.

~/Desktop/new_folder $ cd ..
~/Desktop $ pwd
/Users/wsv/desktop

Advanced developers can use their keyboard and command line to navigate through their computer with ease; with practice this approach is much faster than using a mouse.

In this book I’ll give you the exact instructions to run–you don’t need to be an expert on the command line–but over time it’s a good skill to have for any professional software developer. Two good free resources for further study are the Command Line Crash Course and CodeCademy’s Course on the Command Line.

Install Python 3 on Mac OS X (click here for Windows or Linux)

Although Python 2 is installed by default on Mac computers, Python 3 is not. You can confirm this by typing python --version in the command line console and hitting Enter:

$ python --version
Python 2.7.13

To check if Python 3 is already installed try running the same command using python3 instead of python.

$ python3 --version

If your computer outputs 3.6.x (any version of 3.6 or higher) then skip ahead to creating a virtual environment. However most likely you’ll see an error message since we need to install Python 3 directly.

Our first step is to install Apple’s Xcode package, so run the following command to install it:

$ xcode-select --install

Click through all the confirmation commands (Xcode is a large program so this might take a while to install depending on your internet connection).

Next, install the package manager Homebrew via the longish command below:

$ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

To confirm Homebrew installed correctly, run this command:

$ brew doctor
Your system is ready to brew.

And now to install the latest version of Python, run the following command:

$ brew install python3

Now let’s confirm which version was installed:

$ python3 --version
Python 3.6.4

To open a Python 3 interactive shell–this lets us run Python commands directly on our computer–simply type python3 from the command line:

$ python3
Python 3.6.4 (default, Jan  7 2018, 13:05:00)
[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.39.2)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>>

To exit the Python 3 interactive shell at any time type Control-d (the “Control” and “d” key at the same time).

You can still run Python shells with Python 2 by simply typing python:

$ python
Python 2.7.13 (default, Dec 18 2016, 07:03:39)
[GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.42.1)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

Install Python 3 on Windows

Python is not included by default on Windows, however we can check if any version exists on the system. Open a command-line console by entering command on the Start Menu. Or you can hold down the SHIFT key and right-click on your desktop, then select Open Command Window Here.

Type the following command and hit RETURN:

python --version
Python 3.6.4

If you see output like this, Python is already installed. Most likely it will not be!

To download Python 3, go to the downloads section of the official Python website. Download the installer and make sure to click the Add Python to PATH option, which will let use use python directly from the command-line. Otherwise we’d have to enter our system’s full path and modify our environment variables manually.

After Python has installed, run the following command in a new command-line console:

python --version
Python 3.6.4

If it works, you’re done!

Install Python 3 on Linux

Adding Python 3 to a Linux distribution takes a bit more work. Here are recommended recent guides for Centos and for Debian. If you need additional help adding Python to your PATH please refer to this Stack Overflow answer.

Virtual Environments

Virtual environments are an indispensable part of Python programming. They are an isolated container containing all the software dependencies for a given project. This is important because by default software like Python and Django is installed in the same directory. This causes a problem when you want to work on multiple projects on the same computer. What if ProjectA uses Django 2.0 but ProjectB from last year is still on Django 1.10? Without virtual environments this becomes very difficult; with virtual environments it’s no problem at all.

There are many areas of software development that are hotly debated, but using virtual environments for Python development is not one. You should use a dedicated virtual environment for each new Python project.

Historically Python developers have used either virtualenv or pyenv to configure virtual environments. But in 2017 prominent Python developer Kenneth Reitz released Pipenv which is now the officially recommended Python packaging tool.

Pipenv is similar to npm and yarn from the Node ecosystem: it creates a Pipfile containing software dependencies and a Pipfile.lock for ensuring deterministic builds. “Determinism” means that each and every time you download the software in a new virtual environment, you will have exactly the same configuration. Sebastian McKenzie, the creator of Yarn which first introduced this concept to JavaScript packaging, has a concise blog post explaining what determinism is and why it matters.

The end result is that we will create a new virtual environment with Pipenv for each new Django Project.

To install Pipenv we can use pip3 which Homebrew automatically installed for us alongside Python 3.

$ pip3 install pipenv

Install Django

To see Pipenv in action, let’s create a new directory and install Django. First navigate to the Desktop, create a new directory django, and enter it with cd.

$ cd ~/Desktop
$ mkdir django
$ cd django

Now use Pipenv to install Django.

$ pipenv install django

If you look within our directory there are now two new files: Pipfile and Pipfile.lock. We have the information we need for a new virtual environment but we have not activated it yet. Let’s do that with pipenv shell.

$ pipenv shell

If successful you’ll see parentheses on your command line with the environment activated. It will take the format of the directory name and random characters. On my computer, I see the below but you will see something slightly different.

(django-JmZ1NTQw) $

This means it’s working! Create a new Django project called test with the following command. Don’t forget that period . at the end which will create the project in the current directory. If you don’t explicitly specify the location Django will create a directory before your Django directory.

(django-JmZ1NTQw) $ django-admin startproject test_project .

Now let’s confirm everything is working by running Django’s local web server.

(django-JmZ1NTQw) $ python manage.py runserver

If you visit http://127.0.0.1:8000/ you should see the following image:

Django welcome page

To stop our local server type Control-c. Then exit our virtual environment using the command exit.

(django-JmZ1NTQw) $ exit

We can always reactivate the virtual environment again using pipenv shell at any time.

We’ll get lots of practice with virtual environments in this book so don’t worry if it’s a little confusing right now. The basic pattern is to install new packages with pipenv, activate them with pipenv shell, and then exit when done with exit.

It’s worth noting that only one virtual environment can be active in a command line tab at a time. In future chapters we will be creating a brand new virtual environment for each new project. Either make sure to exit your current environment or open up a new tab for new projects.

Install Git

Git is an indispensable part of modern software development. It is a version control system which can be thought of as an extremely powerful version of track changes in Microsoft Word or Google Docs. With git, you can collaborate with other developers, track all your work via commits, and even revert to any previous version of your code even if you accidentally delete something important!

On a Mac, because Homebrew is already installed we can simply type brew install git on the command line:

$ brew install git

On Windows you should download Git from Git for Windows. Click the “Download” button and follow the prompts for installation. Hit “next” on all steps except the fifth one, “Adjusting your PATH environment.” Instead choose the bottom option: “Use Git and optional Unix tools from the Windows Command Prompt.”

Once installed, we need to do a one-time system setup to configure it by declaring the name and email address you want associated with all your Git commits (more on this shortly).

Within the command line console type the following two lines. Make sure to update them so that Your Name is…your name, and replace [email protected] with your real email address.

$ git config --global user.name "Your Name"
$ git config --global user.email [email protected]

You can always change these configs later if you desire by retyping the same commands with a new name or email address.

Text Editors

The final step is our text editor. While the command line is where we execute commands for our programs, a text editor is where the actual code is written. The computer doesn’t care what text editor you use–the end result is just code–but a good text editor can provide helpful hints and catch typos for you.

Experienced developers often prefer using either Vim or Emacs, both decades-old, text-only editors with loyal followings. However each has a steep learning curve and requires memorizing many different keystroke combinations. I don’t recommend them for newcomers.

Modern text editors combine the same powerful features with an appealing visual interface. My current favorite is Visual Studio Code which is free, easy to install, and enjoys widespread popularity. If you’re not already using a text editor, download and install Visual Studio Code now.

Conclusion

Phew! Nobody really likes configuring a local development environment but fortunately it’s a one-time pain. We have now learned how to work with virtual environments and installed the latest version of Python and git. Everything is ready for our first Django app.

Continue on to Chapter 2: Hello World app.