XCode

Some of the above software must be compiled and therefore we need to install XCode. You can find XCode on your Snow Leopard DVD or at the Apple developers website. Installing XCode is really straight forward and I expect that everyone that is interested in this kind of articles knows how to install it.

Mercurial

We will first install Mercurial for downloading the most recent versions of some of the Python packages that are on Bitbucket. We won’t use MacPorts but just compile it by hand¹.

Let’s launch the Terminal from your ‘’Applications’’ folder and start with editing your .profile so you have /url/local/bin on your $PATH. I’m using Vim, so I will edit it by typing vim .profile inside the terminal and add the following code:

export PATH="/usr/local/bin:/usr/local/sbin:$PATH"
export PYTHONPATH=/usr/local/lib/python2.6/site-packages

Save and close the file (:wq or ZZ in Vim) and apply the new changes by typing source ~/.profile in your terminal.

We can now download and install Mercurial. First download the source in your sources directory. Mine is /Sources (mkdir ~/Sources if you want the same).

cd ~/Sources
curl -O http://mercurial.selenic.com/release/mercurial-1.3.1.tar.gz

And finally let’s build and install.

tar xzvf mercurial-1.3.1.tar.gz
cd mercurial-1.3.1
make all
sudo make install
cd ..

We can check if Mercurial got installed successfully by typing which hg. You should get /usr/local/bin/hg.

Git

Now let’s install Git, also needed for some packages that are on Github. Go to the ~/Sources folder again and do the following:

curl -O http://kernel.org/pub/software/scm/git/git-1.6.4.4.tar.bz2
tar xzvf git-1.6.4.2.tar.bz2
cd git-1.6.4.4
./configure --prefix=/usr/local
make
sudo make install
cd ..

Verify it installed correctly with which git. You should see /usr/local/bin/git.

PIP

PIP is a Python package manager that works well with Virtualenv because you can say in which ‘’Virtual Environment’’ you want to install the package. You can also supply PIP with an requirements file which lists all the packages used in the project. More abouth this later, let’s install it first:

sudo easy_install pip==dev

Virtualenv and Virtualenvwrapper

Virtualenv supplies you with a isolated Python environment for all your Django projects. The production version didn’t work with Snow Leopard yet, so you must install the latest version from the repository. You can do that with:

sudo easy_install http://bitbucket.org/ianb/virtualenv/get/tip.zip

Virtualenvwrapper will make it easier to switch between environments. Let’s install that also:

sudo easy_install virtualenvwrapper

We will need to add two lines to our ~/.profile to make it work.

export WORKON_HOME=$HOME/Sites/virtualenvs
source /usr/local/bin/virtualenvwrapper_bashrc

Make sure that WORKON_HOME is the directory where you will have your Virtual environments. After you have run source ~/.profile you can use the package by typing workon.

Imaging (PIL) with JPEG and Freetype2 support

Almost every Django project will make use of the Python Imaging library. To be able to use this with libjpeg and Freetype2 you must have some extra libraries installed. Let’s start with libjpeg by going to your ~/Sources directory and typing the following commands²:

curl -O -L http://downloads.sourceforge.net/project/libjpeg/libjpeg/6b/jpegsrc.v6b.tar.gz
tar xzvf jpgscr.v6b.tar.gz
cd jpeg-6b
cp /usr/share/libtool/config/config.sub .
cp /usr/share/libtool/config/config.guess .
./configure --enable-shared --enable-static
make

Before installing you may need to create some extra directories.

sudo mkdir -p /usr/local/include
sudo mkdir -p /usr/local/lib
sudo mkdir -p /usr/local/man/man1

You can now install libjpeg.

sudo make install

Next we need to install the Freetype2 library. This is a lot simpler.

cd ~/Sources
curl -O -L http://downloads.sourceforge.net/project/freetype/freetype2/2.3.9/freetype-2.3.9.tar.gz
tar xvfz freetype-2.3.9.tar.gz
cd freetype-2.3.9
./configure && make && sudo make install clean

Combining all the tools

You now have all those great tools installed, but what can you do with them? In this piece I’m going to describe how we work at “Bread & Pepper”:http://breadandpepper.com. You will have your own workflow, but maybe you can get some tips from ours. The first thing I needed was a general Django requirements file for PIP. I have all my virtual environments in my ~/Sites/virtualenvs directory this is also the place for my base requirements file for PIP. Create a new file with vim ~/Sites/virtualenvs/django-basic-requirements.txt and fill it with the following:

# Docutils for admin documentation.
docutils

# Python Imaging Library
http://effbot.org/downloads/Imaging-1.1.6.tar.gz

# Latest Django version
-e svn+http://code.djangoproject.com/svn/django/trunk#egg=Django

Save it :wq. This file supplies us with the packages we use for every Django project. So every time we start a new project, we only have to supply this file to PIP and the rest is magic.

We now need to create a virtualenvs directory and our first Virtual Environment.

cd ~/Sites
mkdir virtualenvs
cd virtualenvs

All our Virtual enviroments will reside in this directory. Let’s start building a site called magicpony.

virtualenv magicpony --no-site-packages

The above command creates a new directory called magicpony.com that is your new isolated Python environment. The --no-site-packages argument makes sure the environment is completely isolated by not inheriting the packages in your system wide $PYTHONPATH.

Now, let’s install our basic Django requirements by supplying the file we created earlier (make sure you’re still in the ~/Sites/virtualenvs directory) to PIP.

pip install -E magicpony.com -r django-basic-requirements.txt

The -E magicpony argument tells PIP to use the magicpony virtual environment. The -r django-basic-requirements.txt argument tells it to look inside a requirements file to know wich packages to install. You can now activate the environment by typing:

workon magicpony.com

If all goes well, you will see (magicpony) placed in front of your prompt. If workon doesn’t work, this could be because you don’t have the right settings for Virtualenvwrapper inside your ~/.profile.

Let’s activate our environment, enter the right directory and create a new Django project:

workon magicpony.com
cd ~/Sites/virtualenvs/magicpony.com
django-admin.py startproject magicpony

Now when we enter the newly created directory, we can go start our Django server with ./manage.py runserver.

Another thing we do is placing a requirements.txt file inside our project directory (also under SCM³) which points to all the specific packages needed for this particular Django project. This way every new developer only has to do the following:

pip install -E magicpony -r virtualenvs/magicpony.com/magicpony/requirements.txt

And they can start working on the new project.

Conclusion

Well, it was a long ride, but now you have a great Django development setup. It certainly made our lives easier by not constantly having to make sure that the right packages were installed. We also use the requirements files for our servers so deployment (with Fabric) goes easy and secure. If you feel that I left something out, or made same errors, please do contact me.