Using both Python 2.x & 3.x
python2.x 설정
virtualenv -p python2.7 ~/Desktop/py27
source ~/Desktop/py27/bin/active
pip install notebook ipykernel
ipython kernel install --user
python3.x 설정
virtualenv -p python3 ~/Desktop/py3
source ~/Desktop/py3/bin/active
pip3 install notebook ipykernel
ipython kernel install --user