Here we will use Homebrew as my package manager for Unix utilities on OSX. Homebrew seems to install less dependencies than Macports or Fink.
Also, most of my Python development has settled on Python 2.7 and occasionally Python 3 for tasks that don’t require external libraries that only run on Python 2.x. So for me, an easier install with less gunk on my hard drive is a fair trade for losing the latest updates to Python 2.4, 2.5, and 2.6.
In this post, I’ll describe my setup.
The first thing to do is uninstall Macports if present. Homebrew has fairly up-to-date versions all of the Unix packages I use on a daily basis, including git, subversion, bash_completion, Python, Qt, PyQt, and their supporting libraries. As such, I don’t need Macports taking up additional hard drive space and potentially causing conflicts with Homebrew’s packages.
Now lets check which is the python we have:
$ which python
Next, I installed (or update) pip, virtualenv, and virtualenvwrapper in my Mac’s default Python (2.7.10 on Mac Capitain 11) via easy_install (or pip itself). If pip is not installed -
sudo easy_install pip
$ easy_install virtualenvwrapper
OR
pip install virtualenvwrapper.
These are usually the only 3rd-party Python packages I install in the system Python’s site-packages folder.
brew update
(If the update fails due to read only access on /usr/local folder, add the following code to .bash_profile file:
alias fix_brew='sudo chown -R $USER /usr/local/'
Source the bash_profile file and call: source .bash_profile
Now on terminal call : fix_brew )
If python 3 is not installed, use -
brew install python3
Next, I remove the Macports configuration from my bash ~/.bash_profile and replace it with the following:
# virtualenvwrapper
export WORKON_HOME=$HOME/VirtualEnvs
if [ -f /usr/local/bin/virtualenvwrapper.sh ]; then
source /usr/local/bin/virtualenvwrapper.sh
fi
# bash completion
if [ -f `brew --prefix`/etc/bash_completion ]; then
. `brew --prefix`/etc/bash_completion
fi
# Python 2.6.1
alias mkve26='mkvirtualenv --no-site-packages'
# Python 2.7.1
alias mkve='mkvirtualenv --no-site-packages --python=/usr/local/Cellar/python/2.7.1/bin/python'
alias mkveqt='mkvirtualenv --python=/usr/local/Cellar/python/2.7.1/bin/python'
alias designer='open /usr/local/Cellar/qt/4.7.2/bin/Designer.app'
# Python 3.5
alias mkve3='mkvirtualenv --no-site-packages --python=/usr/local/Cellar/python3/3.5.0/bin/python3'
# Ammend python path for Homebrew PyQt
export PYTHONPATH=/usr/local/lib/python:$PYTHONPATH
The first couple of sections set up the Terminal for bash completion and virtualenvwrapper commands. The third section sets up my virtualenv aliases: one for the default system python, one for Python 2.7, one for Python 2.7 and PyQt, and another for Python 3.2. Python 3 support was added to virtualenv in version 1.6, so you no longer need to jump through hoops to get it working with Pythyon 2.x.
We use mkve in .bash_profile to create the virtual env for python 2.7. Likewise mkve3 for python 3.5.
Also, workon to switch to python virtual environment.
Now using the virtualenv:
$ mkve py27
Running virtualenv with interpreter /opt/local/bin/python2.7
New python executable in py27/bin/python
Installing setuptools............................done.
virtualenvwrapper.user_scripts Creating /Users/daledavis/VirtualEnvs/py27/bin/predeactivate
virtualenvwrapper.user_scripts Creating /Users/daledavis/VirtualEnvs/py27/bin/postdeactivate
virtualenvwrapper.user_scripts Creating /Users/daledavis/VirtualEnvs/py27/bin/preactivate
virtualenvwrapper.user_scripts Creating /Users/daledavis/VirtualEnvs/py27/bin/postactivate
virtualenvwrapper.user_scripts Creating /Users/daledavis/VirtualEnvs/py27/bin/get_env_details
(py27)$ mkve31 py31
New python executable in /Users/daledavis/VirtualEnvs/py31/bin/python
Installing setuptools..............................................................................................................................................................................................................................................................................................................................done.
(py27)$ python --version
Python 2.7
(py27)$ workon py31
(py31)$ python --version
Python 3.1.2