Install setuptools, pip, and virtualenvwrapper for OS X.

install_python_env_osx.sh

#!/bin/bash
set -e
set -u

PYTHON_VERSION='2.7'   # Change this value if you use a different version of python, e.g., 3.3
PYTHON="python${PYTHON_VERSION}"
PIP="pip-${PYTHON_VERSION}"

echo "Installing most recent version of setuptools."
sudo bash -c 'curl https://bitbucket.org/pypa/setuptools/raw/bootstrap/ez_setup.py | "${PYTHON}"'
echo "Installing most recent version of pip."
sudo bash -c 'curl https://raw.github.com/pypa/pip/master/contrib/get-pip.py | "${PYTHON}"'

USER_SITE_PACKAGES_BIN="${HOME}/Library/Python/${PYTHON_VERSION}/bin"
echo "Adding ${USER_SITE_PACKAGES_BIN} to your PATH."
cat <<'EOF' >> "${HOME}/.bashrc"
# Python user site packages bin
export PATH="${USER_SITE_PACKAGES_BIN}:\${PATH}"
EOF

echo "Installing virtualenv and virtualenvwrapper."
sudo ${PIP} install virtualenvwrapper
VIRTUALENVS_DIR="${HOME}/.virtualenvs"
echo "Making virtualenvs dir at ${VIRTUALENVS_DIR}."
mkdir -p "${VIRTUALENVS_DIR}"
echo "Adding WORKON_HOME."
cat << EOF >> "${HOME}/.bashrc"
export WORKON_HOME="\${HOME}/.virtualenvs"
VIRTUALENVWRAPPER_PATH="/usr/local/bin/virtualenvwrapper.sh"
if [ -f \$VIRTUALENVWRAPPER_PATH ]; then
    source \$VIRTUALENVWRAPPER_PATH
fi
EOF
echo "All done."