pyenv-setup.sh

# install pyenv
git clone https://github.com/yyuu/pyenv.git ~/.pyenv

# setup pyenv and load when shell is loaded
echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bashrc
echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(pyenv init -)"' >> ~/.bashrc

# source the new bashrc
. ~/.bashrc

# install pyenv virtualenvwrapper
git clone https://github.com/yyuu/pyenv-virtualenvwrapper.git ~/.pyenv/plugins/pyenv-virtualenvwrapper

# setup pyenv virtualenvwrapper and load when shell is loaded
echo 'export PYENV_VIRTUALENVWRAPPER_PREFER_PYVENV="true"' >> ~/.bashrc
echo "pyenv virtualenvwrapper" >> ~/.bashrc

# source the new bashrc
. ~/.bashrc

# Now everything is setup. Restart your shell.

# install python 2.7.8
pyenv install 2.7.8
pyenv rehash

# install python 3.4.2
pyenv install 3.4.2
pyenv rehash

# switch the global python version to 2.7.8
pyenv global 2.7.8

# create a virtual environment using python 2.7.8
mkvirtualenv project278

# -- now you can install you python 2 modules

# leave the virtual environment
deactivate


# switch the global python to 3.4.2
pyenv global 3.4.2

# create a virtual environment using python 3.4.2
mkvirtualenv project342

# -- now you can install you python 2 modules

# leave the virtual environment
deactivate

# switch the global python to the system python.
pyenv global system

# swith to environment project278 and check the python version
workon project278
python --version

# swith to environment project342 and check the python version
workon project342
python --version