Digital Adventures of Cyril Pauya

To use multiple Django versions for development, you will need virtualenv. Virtualenv is a sandbox that allows you to use different versions of Python in your development machine.  It is a tool to create isolated Python environments.

I have been using Django 1.1 beta on my projects.  Just recently, I needed to use Django 1.0 for a new project.  Of course there were major differences from Django 1.0 versus Django 1.1 which could cause headaches.

An example is that Django 1.0 uses this on its urls.py:

(r'^admin/(.*)', admin.site.root)

while Django 1.1 uses this on its urls.py:

(r'^admin/', include(admin.site.urls))

So, inorder to use multiple Django versions for development on your machine, you will need:

• internet connection
• setuptools
• pip
• virtualenv
• fix for psycopg2 installation error
• Compiling psycopg2 on Ubuntu
  • $ apt-get install python-dev libpq-dev

Create a virtualenv directory.  This is your working directory for the particular Django version:

$ virtualenv --no-site-packages --unzip-setuptools project-env

Create a requirements.txt to list your required Python applications:

Yolk
Django==1.0.3

Remember to change the 1.0.3 with any Django release version that you want for the virtual environment.

Install your project’s required python applications:

$ pip install -E project-env -r requirements.txt

If you encounter errors in one of the above packages, try installing one package at a time by editing your requirements.txt like this:

# install yolk first
Yolk
#Django==1.0.3

$ pip install -E project-env -r requirements.txt

… edit requirements.txt again…

# install django
#Yolk
Django==1.0.3

$ pip install -E project-env -r requirements.txt

Activate your virtual environment:

$ source project-env/bin/activate

This will change your shell path to show you are inside a virtual environment, and it looks like this:

(project-env) $

Yolk is used to list installed packages in your virtual environment:

(project-env) $ yolk -l

Create a django project:

(project-env) $ cd project-env

(project-env) $ django-admin.py startproject <project name>

And you are done!

Bonus:

To verify which Python version you are using (your global Python packages directory or your virtual Python’s packages directory):

(project-env) $ which python

To verify which django-admin.py you are using:

(project-env) $ which django-admin.py

To de-activate your virtual environment:

(project-env) $ deactivate

Happy Coding!

List of related articles on myListBoard.com:

• django virtualenv
• django fabric virtualenv