Before we get started, let’s just make sure that Python and Django are installed correctly and are the appropriate versions.
Running the following command in the Mac OS or Linux terminal or in the Windows command prompt should show the version of Python. For this workshop you should have a 3.x version of Python.
$ python -V
You should also have pip installed on your machine. Pip is a dependency management tool for installing and managing Python dependencies. First let’s install Django 1.7:
$ pip install Django==1.7 Downloading/unpacking Django==1.7 Downloading Django-1.7-py2.py3-none-any.whl (7.4MB): 7.4MB downloaded Installing collected packages: Django Successfully installed Django Cleaning up...
Things you should type into your terminal or command prompt will always
$ in this workshop. Don’t type the leading
Running the next command will show the version of Django you have installed. You should have Django 1.7 installed.
$ python -c "import django; print(django.get_version())" 1.7
Creating the project¶
The first step when creating a new Django website is to create the project boilerplate files.
$ django-admin.py startproject myblog $ cd myblog
Running this command created a new directory called
myblog/ with a few
files and folders in it. Notably, there is a
manage.py file which is a
file used to manage a number of aspects of your Django application such as
creating the database and running the development web server. Two other key
files we just created are
myblog/settings.py which contains
configuration information for the application such as how to connect to the
myblog/urls.py which maps URLs called by a web browser
to the appropriate Python code.
Setting up the database¶
First, let’s create the database and a super user account for accessing the admin interface which we’ll get to shortly:
$ python manage.py migrate Operations to perform: Apply all migrations: admin, contenttypes, auth, sessions Running migrations: Applying contenttypes.0001_initial... OK Applying auth.0001_initial... OK Applying admin.0001_initial... OK Applying sessions.0001_initial... OK $ python manage.py createsuperuser Username (leave blank to use 'zoidberg'): Email address: email@example.com Password: *** Password (again): *** Superuser created successfully.
After running this command, there will be a database file
in the same directory as
manage.py. Right now, this database only has
a few tables specific to Django. The command looks at
myblog/settings.py and creates database tables for models defined in
Later in this workshop, we will create models specific to the blog we are writing. These models will hold data like blog entries and comments on blog entries.
SQLite is a self-contained database engine. It is inappropriate for a multi-user website but it works great for development. In production, you would probably use PostgreSQL or MySQL. For more info on SQLite, see the SQLite documentation.
The admin site¶
One of the killer features Django provides is an admin interface. An admin interface is a way for an administrator of a website to interact with the database through a web interface which regular website visitors are not allowed to use. On a blog, this would be where the author writes new blog entries.
Let’s check our progress by running the Django test server and visiting the admin site.
In your terminal, run the Django development server:
$ python manage.py runserver
Now visit the admin site in your browser (http://localhost:8000/admin/).
The Django development server is a quick and simple web server used for rapid development and not for long-term production use. The development server reloads any time the code changes but some actions like adding files do not trigger a reload and the server will need to be manually restarted.
Read more about the development server in the official documentation.
Quit the server by holding the control key and pressing C.
Python Package Requirements File¶
$ pip install webtest django-webtest Downloading/unpacking webtest Downloading WebTest-2.0.16.zip (88kB): 88kB downloaded ... Downloading/unpacking django-webtest Downloading django-webtest-1.7.7.tar.gz ... Successfully installed webtest django-webtest six WebOb waitress beautifulsoup4 Cleaning up...
We don’t want to manually install our dependencies every time. Let’s create a requirements file listing our dependencies so we don’t have to type them all out every time we setup our website on a new computer or anytime a package version updates.
First let’s use pip freeze to list our dependencies and their versions:
$ pip freeze Django==1.7 WebOb==1.4 WebTest==2.0.16 beautifulsoup4==4.3.2 django-webtest==1.7.7 six==1.8.0 waitress==0.8.9
We care about the
django-webtest lines here. The other packages are sub-dependencies that were automatically installed and don’t need to worry about them. Let’s create our
requirements.txt file with instructions for installing these packages with the versions we have installed now:
Django==1.7 WebTest==2.0.16 django-webtest==1.7.7
This file will allow us to install all Python dependencies at once with just one command. Whenever our dependency files are upgraded or if we setup a new development environment for our Django website we’ll need to run:
$ pip install -r requirements.txt
Note that we do not need to type this command right now since we have already installed all dependencies.
If you are using virtualenvwrapper (or just virtualenv), you can create a new virtualenv, and test your requirements.txt file. With virtualenvwrapper:
$ mkvirtualenv tddd-env2 $ workon tddd-env2 $ pip install -r requirements.txt $ pip freeze $ deactivate $ workon YOUR_ORIGINAL_VENV
Or with virtualenv:
$ virtualenv venv2 $ source venv2/bin/activate $ pip install -r requirements.txt $ pip freeze $ deactivate $ source venv/bin/activate # or whatever your original virtualenv was