Python on Windows

Download and install Python

1. Click http://python.org/ftp/python/2.7.1/python-2.7.1.msi and choose "run" if you have the option to. Otherwise, save it to your Desktop, then minimize windows to see your desktop, and double click on it to start the installer. If you are running 64-bit Windows or this link doesn't work for any other reason, click Go to http://python.org/download/ and download the latest version of Python 2.7 (2.7.1 at the time of writing). Unless you know otherwise, get the "Windows Installer" version, and not the "Windows X86-64 Installer" version.
2. Use the default settings in the installation prompts and click through until the end of the installer.
3. Open a command prompt (we will be doing this multiple times, so make a note of how to do this!):
   
   If you are using Windows Vista or Windows 7, you should click on the Start menu (the Windows logo in the lower left of the screen), type "cmd" into the Search field directly above the Start menu button, and click on "cmd" in the search results above the Search field. If you are using Windows XP, click on the Start menu (the Windows logo in the lower left of the screen), click on "Run...", type "cmd" without quotes, and hit enter.
   You now have a command prompt open in Windows.
4. At the c:\ prompt that appears, test your Python install by typing

   \Python27\python.exe
   

   and hitting enter. You should see something like

   Python 2.7.1 (r271:86832, ...) on win32
   Type "help", "copyright", "credits" or "license" for more information.
   >>>
   

5. To exit the Python prompt, type exit() and press Enter. This will take you back to the Windows command prompt (the c:\ you saw earlier).

Required step: Put Python on the PATH

You might have noticed that you typed a directory name above when launching Python. In this step, you will reconfigure your computer to put Python on the system PATH so that you can run it without typing the Python27 directory name.

This will take about 5 extra minutes, and it is essential to an easy life using Python down the road.

Get to System Properties

1. Open up "My Computer" by clicking on the Start menu or the Windows logo in the lower-left hand corner, and navigate to "My Computer" (for Windows XP) or "Computer" (For Vista and Windows 7).
2. Right-click on the empty space in the window, and choose Properties

If you're using XP

1. A window labeled "System Properties" will pop up.
   • Click the "Advanced" tab.

If you're not

1. A window labeled "View basic information about your computer" should appear
   • In this window, click "Advanced system settings"
   • A window should appear whose title is "System Properties".

Edit the Path

1. Within System Properties, make sure you are in the tab labeled "Advanced".
2. Click the button labeled "Environment Variables".
   • A window labeled "Environment Variables" should appear.
3. In this window, the screen is split between "User variables" and "System variables". Within "System variables", scroll down and find the one labeled Path. Click the "Edit..." button.
   • A window with the "Variable name" and the "Variable value" should appear. If you have some words listed in the "Variable value", then click in the box to unhighlight it. Make sure that the current path listed in the box is NOT highlighted!
4. In the "Variable value", scroll to the end. Add this text, and hit OK. Make sure to include the semicolon at the start!

   ;c:\python27\;c:\python27\scripts

5. Hit "OK" to close out the system properties changes.
6. Test it:
   • Open up a new command prompt: you do this the same way you did above when installing python. This needs to be a new command prompt or you won't have the shorter paths available for your use!
   • Type just "python" into the command prompt
   • Notice that you now get a Python interpreter.

Success

You have Python installed.

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