7. Completing a Program
“It ain’t over till the fat lady sings.”
Writing a program involves gradually refining your ideas of what you want to do and how you want to express it. In Chapter 6, we produced the initial working version of a calculator program. Here, we’ll refine it. Completing the program — that is, making it fit for users and maintainers — involves improving the user interface, doing some serious work on error handling, adding a few useful features, and restructuring the code for ease of understanding and modification.