Installing Python On Your Home Computer

Note: If you are hoping to use python in your Intro CS class, we strongly recommend using the CS Virtual Machine or x2go. CS installs a large number of python packages that aren't included in the default python install. Some of these are difficult to install; you might find it easier to use one of our prebuilt tools.

Installing Python On Your Home Computer

As of 2015, CS Intro Courses will be using Python 3, so you should download and install Python 3.6.2 ;  if for some reason you want Python 2, here is the link for Python 2.7.13.

At this point, if you're using Mac or Linux, you're done.

If you're using Windows, you will want to pay very close attention to the options in the dialog pane. In particular, you want to check the "Install Launcher for all users" and the "Add Python 3.6 to PATH" options. A preview of this pane can be found in the upper right corner of this web page.

If, when the installation finishes, you are prompted to extend the maximum length of your path variable, please do so.

To test the installation:

  1. Open if you are on a Mac, or a "Command Prompt" if you are on Windows.
  2. Type "python" without the double quotes.
  3. You should see a python prompt; try entering "1+1", if you get "2" then everything is running correctly.

If you are looking for a windows editor that has more functionality then you might try Atom, which is freely available from

If you run into trouble, please contact Mike Tie (, x4067, CMC305).