Modular Programming with Python

The fly in the ointment – changing requirements

Of course, nothing is ever really finished. Let's pretend that you wrote the Charter library and have been busily extending it for several months, adding more data series types and lots of options. The library is being used in several big projects for your company, the output looks fantastic, and everyone seems to be very happy with it—until the day that your boss comes in and says, "It's too fuzzy. Can you take the fuzziness away?"

You ask what he means, and he says that he's been printing the charts out on a high-resolution laser printer. The results aren't good enough for him to use in his company reports. He takes a printout and points to the heading. Looking closely, you can see what he means: ...