OSX set up Python (Anaconda)

Download and install Python

If you use a Mac, you already have Python installed on your computer. However, in order to be able to do all the exercises and participate in the afternoon breakout sessions, we recommend that you also install a collection of Python add-ons called Anaconda. Anaconda includes many useful packages that allow you to perform more powerful data analysis and visualization with Python. Although the collection includes all free software, it is put together by a commercial company called Continuum Analytics.

To install Python, you should:

• Download and install the Anaconda that includes Python 3.4:
  1. First, visit the Anaconda download page.
  2. Click the blue text to the right side of the penguin logo that says "I WANT PYTHON 3.4".
  3. Click on top button on the right side of the same box under the text "CHOOSE YOUR INSTALLER". The button should say something like MAC OSX 64-bit Python 3.4 Graphical Installer.
• Once the program is downloaded, run the downloaded file which should launch a graphical installer.
• Use all of the defaults for installation, except make sure to check Make Anaconda the default Python.

Note In addition to the 360MB file you will download, the installation will take several hundred megabytes for the 64-bit installer (which is most likely the version you'll be installing.)

To install Anaconda, you should:

1. Download and install Anaconda. Follow this link to the Anaconda website and click on the button that says Download OSX -- 64-Bit Python 2.7 Graphical Installer.
2. Download the file to your Desktop or Downloads folder.
3. Once the (~275 MB) installer package is downloaded, double click the .pkg file and follow the instructions on the screen. Install Anaconda in your home folder.

Install notes

• The website may ask you for your email address at some point during the install process. If so, there is no reason to leave the checkbox marked saying that you want mail from Continuum.
• This install will take approximately 890MB for the 64-bit installer (which is most likely the version you'll be installing.) If you do not have this much space on your computer, you cannot install Anaconda, but you can still run Python--skip to the section below!
• If you get stuck during the install process, ask a mentor for help. These instructions may also be helpful.
• Anaconda may leave a shortcut called "Launcher" on your desktop. You can delete this link: we won't be using it in the workshop.

Test your Python install

Now that you have installed everything you need, we will make sure we can start a Terminal and run Python from the command line.

1. Start up a Terminal. You can find the Terminal application through Spotlight, or navigate to Applications/Utilities/Terminal.
   
   This Terminal contains something called a command prompt. This command prompt 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 command prompt.
2. Test your Python install at the command prompt. Type

   python
   

   and hit enter. You should see something like

   Python 2.7.1 (r261:67515, Feb 11 2010, 00:51:29) 
   [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.
     
   • If the Python version number (2.7.1 in the example above) is not a number between 2.4 and 2.7 (ignoring the number after the second dot), tell a staff member.
3. To exit the Python prompt, type

   exit()
   

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

Success!

You have tested your Python installation.