Python

Python 2.7.10 comes packages with OS X El Capitan. To install the latest version from homebrew:

brew install python

# pip and setuptools are already installed
pip install --upgrade pip setuptools

# Install virtualenv
pip install virtualenv

Scikit learn

pip install -U scikit-learn
brew install homebrew/python/numpy
brew install homebrew/python/scipy

Numpy depends on gcc, and if it isn’t installed, homebrew will try to download and compile it from source, which could take an hour or more to compile.

Flask

sudo easy_install pip

brew install python
pip install virtualenv

mkdir foo-project
cd foo-project

virtualenv venv
. venv/bin/activate

python app.py

Numpy

Guide to Numpy [PDF] by Travis E. Oliphant