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So in the last lesson, we saw how to create a turtle that does a random walk.

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Now in this lesson,

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I want to show you how you can create a random color for your turtle drawing

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rather than just using the named colors and then picking a random one out of the

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list. When you take a look at the pen color of the turtle,

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you can see that you can use a color string such as what we've been doing using

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red, yellow, or a hex string that represents the color,

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or we can use a RGB color.

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And the RGB color is going to be represented by a tuple of different amounts of

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red, green, and blue. So what exactly is a tuple?

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Well,

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a tuple is a data type in Python and it looks like this.

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It has round brackets around it

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and then each of the items inside are separated by a comma.

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So does this remind you of another data type?

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Does it not look a little bit like a list? Well,

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indeed a tuple is very similar to a list. Each of the items that go into the

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tuple are ordered.

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So let's pull up my Python console here and let's create my tuple 

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which is denoted by a set of round parentheses

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and then let's put in three items, 1, 3, and 8,

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and there we have created a new tuple.

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Now in order to get hold of any of those items in there,

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I can write the name of the variable and then using square brackets

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I can access the index.

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So 1 is going to be at position zero, 3 is going to be at position one and

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8 is going to be at position two. So if I hit enter on this,

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then you can see that's going to be equal to 8.

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And if you click this drop down on the right,

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you can see the same representation; position 0, 1,  2,

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and those pieces of data and the total length is three.

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So at this point you might be asking yourself, well, I already know about lists,

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so why do I need to know about tuples? What's the difference anyways? Well,

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a tuple is going to be carved in stone

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so you can't change the values like you can with lists.

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For example, if I wanted to say

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get hold of my tuple and instead of the 8 at position two,

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I want to change it to 12. Now, if I go ahead and hit enter,

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you can see I get a error and this is a type error.

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This particular type, tuple, does not support item assignment.

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So I can't just change it willingly like this.

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And I also can't remove items from the tuple,

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I can't change it in any way. Once you've created your tuple 

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you can consider it as carved in stone and it is what we call immutable.

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It cannot be changed. So why would you use a tuple then?

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Well, think about the times

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like say if you're creating a color scheme for your website or are you creating

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some sort of list that you want to stay constant and you don't want somebody to

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accidentally change it or accidentally mess it up, well,

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then you might want to consider using a tuple.

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And if you find yourself creating a tuple and then realizing, Oh,

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actually I need to change it well,

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then you can simply put your tuple inside a list like this,

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and you can actually convert it into a list.

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Coming back to our documentation,

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the color is represented by a tuple because if you define a color,

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you're unlikely to change it.

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And then we have a r, g, and b,

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which is in the range between zero and the color mode.

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So the mode can be between 0 and 1 or 0 and 255. In the course resources,

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I've linked to this really handy RGB calculator tool,

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which demonstrates how RGB colors work so perfectly.

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You can see that if we have zero amount of red, zero amounts of green,

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zero amounts of blue, we get black.

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But if we mix different amounts of red and different amounts of green and

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different amounts of blue, then we can get all of the colors in the rainbow.

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The three primary colors can create any color that you dream of.

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And each of these sliders,

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you can see, goes from 0 all the way up to 255.

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So more red, more green or more blue.

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And this is what the RGB color ends up looking like.

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I find it easier to think about the range between 0 and 255.

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So in turtle,

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we actually have to change the color mode to 255.

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So to do this, it's a little bit tricky

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which is why I didn't want to put this as part of the challenge.

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But we have to tap into the actual turtle module and not the turtle object,

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and then change the color mode for that module. Back in our code,

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we can tap into our turtle module

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which is known as 't' in our code.

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And then we can tap into the color mode to make it go from 0 to 255.

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So now that we've changed the color mode, we can now create a random color.

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So let's get rid of this list of colors. Instead,

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I'm going to create a new function called a random_color,

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and this function is going to return a random color using RGB.

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So let's first create a random red.

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So we use the random module and then use the randint and then generate a number

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between 0 and 255.

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And then we can repeat this process for the other two color spaces,

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so green and for blue.

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Now we've got three random numbers,

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one each representing each of the color spaces,

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and then we can generate our tuple. Here's the challenge for you.

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See if you can return from this function

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a tuple that consists of the three random integers, r, g and b,

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and then use that random color to color the turtle drawing instead of this broken

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code which relied on that previous list of colors.

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Pause the video and see if you can complete this challenge.

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All right. So we know that to create a tuple 

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we need a set of round brackets or parentheses,

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and then we're going to put each of these in order,

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so r, g and b. So here's our tuple created,

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and this is basically our new random color.

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And then this function is going to return that random color as the output.

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So now instead of using random.choice and using that previous list,

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all we have to do is get hold of a random color

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that's going to be outputted from this function and then use it to color Tim's

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drawing. So let's run this code again,

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and you should be able to see that in this random walk,

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the color is completely random.

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Pretty much every single turn is going to draw something completely different in

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terms of color.

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And this is achieved by learning a little bit about how colors work and how we

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can generate them using the random RGB colors.