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Some languages have a special control structure, called switch, or case, or

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something like that, that allows you to select from multiple choices of a single variable.

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Python doesn't have one.

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So, we're going to take a look at one particular strategy where you can do this

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very easily within Python, and you'll see that it's not necessarily a weakness in the language;

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it's just different way of looking at things.

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So, we'll go ahead and make a working copy of switch.py, call it switch-working.

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We'll open our working copy, and we'll start by declaring a dictionary. We'll call it

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choices, and we'll just put in a few choices here, one first, two second, three,

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and we'll declare a variable and then we'll select based on that variable.

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So, when I save this and run it, you'll see that we have selected one and we

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printed out first. And if I change this to say three, save that and run it, it'll save third.

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So, here we've been able to very easily select based on a number of choices, and

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we could make this a very long list if we wanted to, and we can add things,

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delete things from the list, and change things in the list, and this will all

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work exactly as expected.

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The one thing this does not do well is if I select something that's not in the

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list, you'll see that we get an error, save that and run it.

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Of course, we can trap this error with try and accept, or there is an even

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easier way to do this. We can use the get method of the dictionary object,

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so you get V comma, and then I can put in a default result, and I can say other.

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And so what that does is it looks for V in the dictionary, and if it doesn't find

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it, it gives you back this value.

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So, if I save that and run it, you can see we get other, because we have seven.

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If I put in five, then I'll get fifth. Save and run and there is fifth.

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So, this is a very simple way to do what most people use switch statements for

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and you'll see some other examples, including an example of executing code based

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on multiple choices, later on in the course.