Documenting my specific tweaks here. I feel this doc does a great job of covering the basics of virtualenv and virtualenvwrapper.
brew update
brew install python
brew install python3
pip install virtualenv
pip install virtualenvwrapperedit ~/.bashr_profile
#file: ~/.bashrc
# pip should only run if there is a virtualenv currently activated
export PIP_REQUIRE_VIRTUALENV=true
## TMP
export WORKON_HOME=$HOME/.virtualenvs
export PROJECT_HOME=$HOME/Projects/python
source /usr/local/bin/virtualenvwrapper.sh
## END TMPNew virtual environment using Python 3
mkvirtualenv --python=$(which python3) MyProjectEnv
This creates a folder MyProjectEnv inside the environments folder ~/.virtualenvs.
The new environment will be active after running the previous command.
To deactivate it, just type:
$ deactivate
and to activate it again
workon MyProjectEnv
While being in your python3 virtual envirnoment, if you type
$ python
you activate python 3! Moreover, you can use pip to call pip3 and install python3 packages.
In order to keep your environment consistent, it's a good idea to "freeze" the current state of the environment packages. To do this, run
$ pip freeze > requirements.txt
This will create a requirements.txt file, which contains a simple list of all the packages in the current environment, and their respective versions. Later it will be easier for a different developer (or you, if you need to re-create the environment) to install the same packages using the same versions:
$ pip install -r requirements.txt