Install

Install python and python2 using HomeBrew.

brew install python python@2

Python are installed in /usr/local/Cellar/python@3.x via HomeBrew.

Symlinks are created in /usr/local/bin/ in addition to /usr/local/opt/.

To create symlink manually, e.g. brew link python3, which will create symbolic link in /usr/local/bin/python3 that points to /usr/local/Cellar/python@3.x/3.x.x/bin/python3.

The message after installation:

Unversioned symlinks python, python-config, pip etc. pointing to python3, python3-config, pip3 etc., respectively, have been installed into /usr/local/opt/python@3.x/libexec/bin

which means to let python, pip start python3 and pip3 (referred from here):

echo 'export "PATH=/usr/local/opt/python@3.x/libexec/bin:$PATH"' >> ~/.zshrc

Install Python packages with pip:

/usr/local/opt/python@3.x/bin/pip3 <package>

They will install into the site-package directory

/usr/local/bin/python3.x/site-packages

To let the installed python@3.x first in PATH:

echo 'export "PATH=/usr/local/opt/python@3.x/bin:$PATH"' >> ~/.zshrc

For compilers to find python@3.x:

export LDFLAGS="-L/usr/local/opt/python@3.x/lib"

For pkg-config to find python3.x:

export PKG_CONFIG_PATH="/usr/local/opt/python@3.x/lib/pkgconfig"

Install virtualenv & virtualenvwrapper

python3 -m pip install virtualenv
python3 -m pip install virtualenvwrapper

Configuration

export WORKON_HOME=$HOME/.virtualenv
export VIRTUALENVWRAPPER_PYTHON=/usr/local/bin/python3
export VIRTUALENVWRAPPER_VIRTUALENV=/usr/local/bin/virtualenv
source /usr/local/bin/virtualenvwrapper.sh

During startup, virtualenvwrapper.sh finds the first python and virtualenv programs on the $PATH and remembers them to use later. It is import for the PATH to be set before sourcing virtualenvwrapper.sh.

To override the $PATH search, set the variable VIRTUALENVWRAPPER_PYTHON to the full path of the interpreter to use and VIRTUALENVWRAPPER_VIRTUALENV to the full path of the virtualenv binary to use. Both variables must be set before sourcing virtualenvwrapper.sh.

Quick-Start

Run workon to see a list of environments.

Run mkvirtualenv temp to create an environment called temp.

Run workon temp to enter the environment.

Run rmvirtualenv temp to remove.