osx_python_installation.mkd

Installing Python on OSX

This page walks through how to install a version of Python on OSX that is compatible with this tutorial.

Any version of Python 3 will work for this tutorial. If you don't have Python installed, we'll install Python version 3.4.1.

If you already have Python installed, check the Python version: if the version number starts with a 3 (as opposed to a 2), you can use it for this class and can skip to checking your Python installation.

Download and install Python

• If you are running OS X version 10.6 or later, click https://www.python.org/ftp/python/3.4.1/python-3.4.1-macosx10.6.dmg to download the Python installer.
• If you are running OS X version 10.5, click and download the Python installer from https://www.python.org/ftp/python/3.4.1/python-3.4.1-macosx10.5.dmg instead.
• If you have a version of OS X older than 10.5, please upgrade to a newer version of OS X before installing Python.

Once the download is complete, double-click on the installer to run it and complete the installation.

Checking your Python installation

1. Start up a Terminal. You can find the Terminal application through Spotlight, or navigate to Applications/Utilities/Terminal.
   
   This terminal is another way of navigating your computer and running programs -- just textually instead of graphically. We are going to be running Python and Python scripts from this Terminal prompt.
2. Test your Python install at the command prompt. Type

   python3
   

   and press Enter. You should see something like

   Python 3.4.1 (v3.4.1:d047928ae3f6, May 13 2013, 12:45:22) 
   [GCC 4.2.1 (Apple Inc. build 5646)] on darwin
   Type "help", "copyright", "credits" or "license" for more information.
   >>>
   

   You just started Python! The >>> indicates that you are at a new type of prompt -- a Python prompt. The command prompt let's you navigate your computer and run programs, and the Python prompt lets you write and run Python code interactively.
   

3. To exit the Python prompt, type

   exit()
   

   and press Enter. This will take you back to the OS X terminal prompt.

Success!

You have Python installed and tested.

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Questions? Please don't hesitate to reach out to the author (me, Jessica!) at: [email protected].