Once you have created a Python program, you see the program name displayed in the folder where you saved it. You can try to run it in the same way that you run other programs (e.g., by double-clicking on it). For many Python programs, when you activate them in this way, you either see nothing happening, or a quick flash of a black window, after which nothing happens anymore. The reason is that Python programs run in a “command-line shell” of the operating system. If you are not a Linux user, this is probably not something that you are used to. Basically, what happens is that Python opens the command-line shell, runs the program, and when the program finishes, closes the shell, giving you the feeling that nothing has happened. But something did happen; you just did not notice it.

For the purpose of most of this book, you should simply run programs in the editor that you use, as I describe for IDLE above. You may open the command-line shell (which usually is a somewhat hidden option in the list of installed programs on your machine, falling under System Commands) and “manually” run Python programs from that shell, but there seldom is a need to do that.