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Sometimes when you're defining a function, you might need an arbitrary number of arguments.

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Arguments that aren't necessarily going to be used every time and aren't

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necessarily going to even be named, perhaps a list of things.

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Python has a facility for this and let's see how that works.

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We'll go ahead and make a working copy of functions.py, call it

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functions-working.py and we'll open that working copy up and here we have our

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little test function.

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And let's say that we just want to give it an arbitrary list of arguments and so

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that's done simply like that.

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The asterisk is special in this place as it means that this is just a list

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of optional arguments.

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You can have before it-- you can have a named argument or several of them.

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you could have this, that and the other, and then after all of that you can have

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your optional arguments, and so when you call it you might need to give it some

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actual values there and then you could have your arbitrary number of optional

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arguments like that.

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So if we want to list those, we can just get rid of this text here and say

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this, that, and other, and if we save that and run it, you'll notice that we get

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the 1, 2 and the 3.

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What about these other ones?

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If I say args, what I'll get is I'll get a tuple with those values.

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Save that and run it and there is our tuple.

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So you can see that it's just a normal tuple, as in Python, and so I can use it

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as an Iterator if I want to. I can say for n in args like that, print n, end,

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equals blank or let's give it a space like that. And I can save it and run it

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and now we have our arbitrary arguments after our named arguments.

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So, it's good to keep in mind that this is a tuple.

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That means that it is immutable, can't add to it or change anything in it, but

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it is an excellent way to get an arbitrary list of arguments into a function.