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4: Case study - interface design

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    This chapter presents a case study that demonstrates a process for designing functions that work together.

    It introduces the turtle module, which allows you to create images using turtle graphics. The turtle module is included in most Python installations, but if you are running Python using PythonAnywhere, you won’t be able to run the turtle examples (at least you couldn’t when I wrote this).

    If you have already installed Python on your computer, you should be able to run the examples. Otherwise, now is a good time to install. I have posted instructions at

    Code examples from this chapter are available from

    This page titled 4: Case study - interface design is shared under a CC BY-NC 3.0 license and was authored, remixed, and/or curated by Allen B. Downey (Green Tea Press) .

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