O'Reilly Introduction to Python/Section 1/OSX set up Python

We are going to 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 this link 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

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.
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.
To exit the Python prompt, type
```
exit()
```
and press Enter. This will take you back to the OS X terminal prompt.

Success!

You have tested your Python installation.

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