Python is already installed in Mac OS and can be accessed from a terminal window (terminal application can be found under applications - utilities). To install pygtk, which adds some graphical extensions, download the package from the link provided. When you try to install the package, the operating system may prevent it for security reasons (because the software is not from apple). To temporarily disable the security measure, type in the terminal sudo spctl --master-disable Install the package, then re-enable the security measure with sudo spctl --master-enable "sudo" means superuser mode and your account must have this privilege (usually you do). Download one of the programs on the class webpage that uses gtk (such as basic drawing template) and run it by typing python programname.py