Python on Windows

From OpenHatch wiki
Revision as of 17:30, 12 May 2011 by imported>Jesstess
Jump to navigation Jump to search

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. Follow the installer instructions to completion.
  2. Open a command prompt (we will be doing this multiple times, so make a note of how to do this!):
    • On Windows Vista or Windows 7: 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.
    • On Windows XP: click on the Start menu (the Windows logo in the lower left of the screen), click on "Run...", type cmd into the text box, and hit enter.

    You now have 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.
  3. At this 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.
    >>>
    

    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.

  4. 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.

« Back to the Friday setup page