Learning Python, 3rd Edition

Chapter 3. How You Run Programs

OK, it’s time to start running some code. Now that you have a handle on program execution, you’re finally ready to start some real Python programming. At this point, I’ll assume that you have Python installed on your computer; if not, see the prior chapter and Appendix A for installation and configuration hints.

There are a variety of ways to tell Python to execute the code you type. This chapter discusses all the program-launching techniques in common use today. Along the way, you’ll learn how to type code interactively, and how to save it in files to be run with system command lines, icon clicks, module imports, IDE GUIs such as IDLE and Eclipse, and more.

If you just want to find out how to run a Python program quickly, you may be tempted to read the parts that pertain only to your platform and move on to Chapter 4. But don’t skip the material on module imports, as that’s essential to understanding Python’s program architecture. I also encourage you at least to skim the sections on IDLE and other IDEs, so you’ll know what tools are available for when you start developing more sophisticated Python programs.

Interactive Coding

Perhaps the simplest way to run Python programs is to type them at Python’s interactive command line. There are a variety of ways to start this command line—in an IDE, from a system console, and so on. Assuming the interpreter is installed as an executable program on your system, the most platform-neutral way to start an interactive ...