Getting Started§

Your Development Environment§

Isolation§

• We want to avoid using unknown dependencies, or unknown versions
• virtualenv provides an easy way to work on a project without your system's site-packages

Determinism§

• Determinism is all about dependency management
• Choose a tool, use it in development and production
  • pip, specifically a requirements files
  • buildout
  • install_requires in setup.py
• Identify specific versions of dependencies

Similarity§

• Working in an environment similar to where you deploy eliminates variables when trying to diagnose an issue
• If you're building something that requires additional services, this becomes even more important.
• Vagrant is a tool for managing virtual machines, lets you easily create an environment separate from your day to day work.

Setting Up Your Environment§

Create a Clean Workspace§

$ mkdir tutorial
$ virtualenv ./tutorial/
New python executable in ./tutorial/bin/python
Installing setuptools............done.
Installing pip...............done.
$ source ./tutorial/bin/activate
(tutorial)$

Start a Requirements File§

Create a requirements.txt in the tutorial directory with a single requirement in it.

Django==1.5.1

Installing Requirements§

And then we can use pip to install the dependencies.

(tutorial)$ pip install -U -r requirements.txt

Downloading/unpacking Django==1.5.1
  Downloading Django-1.5.1.tar.gz (8.0MB): 8.0MB downloaded
  Running setup.py egg_info for package Django

    warning: no previously-included files matching '__pycache__' found under directory '*'
    warning: no previously-included files matching '*.py[co]' found under directory '*'
Installing collected packages: Django
  Running setup.py install for Django
    changing mode of build/scripts-2.7/django-admin.py from 644 to 755

    warning: no previously-included files matching '__pycache__' found under directory '*'
    warning: no previously-included files matching '*.py[co]' found under directory '*'
    changing mode of /home/nathan/p/edt/bin/django-admin.py to 755
Successfully installed Django
Cleaning up...

Beginning a Django Project§

Creating the Project§

(tutorial)$ django-admin.py startproject addressbook .

manage.py
./addressbook
    __init__.py
    settings.py
    urls.py
    wsgi.py

Project Scaffolding§

manage.py

Wrapper around django-admin.py that operates on your project. You can run the tests or the development server using this.

settings.py

Your project configuration.

urls.py

URL definitions for your project

wsgi.py

A wrapper for running your project in a WSGI server.

Creating the "App"§

(tutorial)$ python ./manage.py startapp contacts

./addressbook
./contacts
    __init__.py
    models.py
    tests.py
    views.py