Data Science from Scratch

Chapter 2. A Crash Course in Python

People are still crazy about Python after twenty-five years, which I find hard to believe.

Michael Palin

All new employees at DataSciencester are required to go through new employee orientation, the most interesting part of which is a crash course in Python.

This is not a comprehensive Python tutorial but instead is intended to highlight the parts of the language that will be most important to us (some of which are often not the focus of Python tutorials).

The Basics

Getting Python

You can download Python from python.org. But if you don’t already have Python, I recommend instead installing the Anaconda distribution, which already includes most of the libraries that you need to do data science.

As I write this, the latest version of Python is 3.4. At DataSciencester, however, we use old, reliable Python 2.7. Python 3 is not backward-compatible with Python 2, and many important libraries only work well with 2.7. The data science community is still firmly stuck on 2.7, which means we will be, too. Make sure to get that version.

If you don’t get Anaconda, make sure to install pip, which is a Python package manager that allows you to easily install third-party packages (some of which we’ll need). It’s also worth getting IPython, which is a much nicer Python shell to work with.

(If you installed Anaconda then it should have come with pip and IPython.)

Just run:

pip install ipython

and then search the Internet for solutions to whatever cryptic ...