Scaffold Your First Django API
Part I: Environment Setup
Starting any new language or framework can be intimidating. Breathe.
“I’m sure everything I learned in Ruby/Rails will immediately transfer over and apply directly to Django/Python.” — said no one ever
You never realize how much you get for free with Active Record and Rails until you start a new backend framework. After completing my capstone project, I learned:has_many and belongs_to are some of the most powerful code blocks on the planet. Those two lines in a Rails relationship model provide for so many connections throughout your database. That being said, applying yourself to a Django project can teach you a lot more on database structures and relationships.
To get started, you’ll first need to download Python:(https://www.python.org/downloads/). You’ll want to install this globally. I’ve been using Python 3.7.9 and don’t think I’ve run into any issues. I have been told downloading the latest version (at the time of this writing 3.9), can sometimes create dependency issues.
Next, create a project folder in a good place you want to store your files.
After creating a project folder, run the following command while in this directory in your terminal:
virtualenv --python=python3 venv
This just lets your machine know you want all future python commands to equal python3 (so you don’t have to type out python3 every command).
Next:
source venv/bin/activate
This installs a virtual environment within your project’s folder. Creating a virtual environment helps with Django version control when multiple developers are working on the same project. For more detail on this, I thought this was a helpful article: https://medium.com/@dakota.lillie/an-introduction-to-virtual-environments-in-python-ce16cda92853.
I use zsh as a terminal interface, but under most terminals, you should see a (venv) to the left of your folder directory. Now, it’s time to install Django (within the virtual environment):
pip3 install django djangorestframework django-cors-headers
Following installation of these three packages, you can now run:
django-admin start project django_project
I suggest re-naming the django_project folder you just created to src, like this, so that you don’t get confused between the two folder paths:
Great, now, this is very important, and you should be able to figure out what you’re doing wrong if you don’t do this, but change directories into your src folder now with:
cd src
Within the src folder, run:
python manage.py runserver
If you go to localhost:8000 on your browser, you should see this:
Congrats!! You’re on Django. Give yourself a pat on the back for taking this leap. Let’s keep going but creating a couple of more basic scaffolding instructions.
The default database for Django is SQLite (same as Rails). SQLite is fine for your microwave, or even your car’s clock, or anything that doesn’t need to be connected to the internet, but wouldn’t be the preferred route to go if you ever plan on deploying your project to the world. To install a PostgresDB package, run:
pip3 install psycopg2
I initially had some troubles setting up Postgres at first, particularly with that last command above. You may get a massive red error message at first, I know myself and another cohort mate of mine did. It’s hard to remember exactly what I did to de-bug, but it wasn’t too difficult to run a couple of commands to move past the error message.
I’ve enjoyed using pgAdmin4 for a Postgres interface. Within PGAdmin, toggle down the server icon on the left and the database icon underneath that. Right click on the database icon and click “create”. This create a database table. Chose a name for your database however you want (e.g. dogs, cats, or animals). Click save and you can close out of PGAdmin.
Back in your code file, delete your SQLite database. The database would have been created after running your server initially. In your settings.py file, within your django project, remove or comment lines 76–81 (any reference to SQLite). Add the following, like so:
# Database# https://docs.djangoproject.com/en/3.1/ref/settings/#databases# DATABASES = {# 'default': {# 'ENGINE': 'django.db.backends.sqlite3',# 'NAME': BASE_DIR / 'db.sqlite3',# }# }DATABASES = {'default': {'ENGINE': 'django.db.backends.postgresql_psycopg2','NAME': 'animals','USER': 'postgres','PASSWORD': "your postgres password goes here",'HOST': 'localhost','PORT': '5432',}}
I learned the hard way that your password MUST be in “double quotes” as opposed to ‘single quotes’ (but I think that only applies if you have special character in your password). You’ve now replaced the SQLite database with your new Postgres database and are ready to start your first Django app.
Run:
python manage.py startapp django_app
You can name your app however you like, but I’ll keep mine as django_app for this guide. Next, add the following 3 apps to your installed apps list (which is already located ~ halfway down in your settings.py file:
INSTALLED_APPS = [...,'django_app','rest_framework','corsheaders',]
Finally, if you want communication with your frontend, add the following line of code to the end of your middleware, as well as the Boolean statement below the array:
MIDDLEWARE = [
...'corsheaders.middleware.CorsMiddleware',]CORS_ORIGIN_ALLOW_ALL = True
Congrats again. You have now completed the basic structure of your first Django Api. Now, you can actually start putting some data together!
For Part II on setting up your Django API, head on over here:
