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Guys, we've already come really, really far.

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We've done all of this and now we're on this stage, creating a scoreboard.

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So what we want is to be able to write some text in our program that keeps track

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of the score, of how many pieces of food we've actually managed to eat. Now,

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the score should update every single time we hit a new piece of food and it's

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going to stay there and keep updating itself

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every time we hit a new piece of food.

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Now this scoreboard is also going to be a turtle.

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So one of the things that you can do with your turtle is you can get it to write

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a piece of text.

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And this is what the method looks like in the documentation.

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You can tell it what it should write, what kind of alignment you want,

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do you want it to be in the center of the screen,

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on the left or right side of the screen? And then what kind of font you want?

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So the font name, font size and font type,

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so normal or heavy or bold or underlined,

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and we would call it more or less like this.

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So here's a challenge for you.

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I want you to go ahead and create a new file called a scoreboard.py.

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And inside this file, I want you to create a new scoreboard class.

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Now,

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this scoreboard class is going to inherit from the turtle class,

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just as we did with the food class.

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And then the scoreboard is going to be a turtle

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which knows how to keep track of the score and how to display it in our program.

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Feel free to choose whatever font you want, whatever size you want,

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but the end outcome we're looking for is something that looks a bit like this

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and the score is going to need to be tracked inside that scoreboard class.

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And it needs to be increased by one every single time the snake eats a piece of

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food. You're going to need the help of the documentation,

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you're going to need to read up on how this turtle.write method works,

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and you're also probably going to need this turtle.clear so that you clear

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the writing every time you update the score.

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Have a think about how you would solve this and then go ahead,

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pause the video and give it a go.

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[inaudible]

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All right.

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So the first thing I'm going to do is I'm going to create my scoreboard class.

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And as I mentioned,

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this class needs to inherit from the turtle class.

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So from the turtle module,

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let's get hold of the actual turtle class so we can use it inside this file.

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And then I'm going to add it to my scoreboard as the superclass.

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Now, if I create my inits,

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I can go ahead and use this light bulb to insert the superclass call.

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So now my scoreboard is a class that can do everything a turtle class do.

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And one of the things I want it to do is I want it to keep track of the score.

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So let's say it starts out at zero,

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and we want to be able to write this onto the screen. So we can say self.

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write, and let's use an f-string to say score,

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and then we can insert the self.score value in here.

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And then we can add whether if we want it to be aligned to the center,

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for example, and then we can also add a font if we need to.

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Let's use the same font as here, Arial,

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and then we're going to make the font size a bit bigger,

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and then we're going to keep it as normal.

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So I'm going to choose an Arial font, size 24,

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and then the style is going to be normal.

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And as you can see here,

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I'm getting a warning here and it's telling me that it expected a tuple,

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but instead it just got a single string.

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So let's just compare this against the documentation code

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and you can see that this is meant to be a tuple instead of just a single piece

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of string. So let me go ahead and fix that.

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Let's add some parentheses around this,

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and then this Arial is going to be a string,

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this 24 is going to be a number and the normal is going to be a string.

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And now our errors have gone away.

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So now going back to our main.py

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let's go ahead and create our scoreboard

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as an object from the scoreboard class,

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which of course means that we need to import it into this file.

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So from the scoreboard file import the Scoreboard class.

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And now if I run this code, somewhere in the middle

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there I've got a scoreboard,

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but because it's actually black, you can't really see it.

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It's really important that we change the color of the scoreboard turtle before

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we write the text,

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because if it was written as black and then we change it to white,

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you still won't notice a difference.

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So if I change the self.color right here to white and I hit run,

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then you can see that scoreboard showing up.

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But if I move this line of code to after we've written it,

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then it won't actually make a difference. It's still written in black

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somewhere on there. Now, in addition,

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we want to get rid of the turtle that shows up when we create our scoreboard

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because all we want it to do is we want it to write,

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we don't want it to actually show up a turtle. Self.hideturtle, and

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now that little arrow disappears.

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And we probably don't want this scoreboard to be bang in the middle.

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So let's move it.

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Let's tell it to go to a particular X and Y position.

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Now, in example, here, I've got it in the center, right at the top.

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So we can keep the X as zero, but let's move the Y further up to the top.

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So let's say something around 270. And now if we test it again,

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you can see that the turtle went to the top,

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but this happened after this line was already written. So again,

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this needs to happen before we write.

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And now if we refresh, you can see it's moved to the top,

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but it's also drawn on a path to do that. So instead of doing that,

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we can tell it to self.penup before it moves to this location.

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There we have it. We've got our score showing up at the top. Now,

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all that's left to do is to keep track of the score and to increase it whenever

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the snake hits a new piece of food.

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So we know that that happens inside this if statement,

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when the snake head collides with the food, then we refresh the food,

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but we also want to increase the score.

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So let's go ahead and create a function inside our scoreboard class called

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increase_score.

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And this function is going to take the self.score and add one to it.

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And then it's going to call self.write.

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So now back inside our main.py,

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we can get whole of our scoreboard object and tell it to increase score

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whenever the snake collides with the food. So let's test this again.

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And if I manage to hit the food, 

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then you can see that the score is being updated,

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but what's happening is that the score is being written on top of the previous

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scores. So it's just all overlapping with each other.

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So instead,

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what we need to do is between each time we update the scoreboard,

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we actually have to delete what was previously on there.

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And because we've now got these two lines

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which are pretty much identical in two places,

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let's go ahead and create a function instead. We'll call update_scoreboard,

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and inside this function, we'll have our self.write.

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And we can call self.update_scoreboard here and also here.

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So now before we increase the score and call update scoreboard,

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we can call self.clear to clear the previous text that was written by this

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turtle, which is the scoreboard. Now, if we run this again

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you can see that when I do score,

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my scoreboard is wiped and then the new text code is written.

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So it doesn't overlap with the previous scoreboard.

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The final thing I want to do just as a finishing touch is I don't like having

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these hard-coded pieces of text inside the body of my programs.

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So instead it would be much better if we could take these pieces of texts out

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and create constants with them.

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So we could have one that's called ALIGNMENT set to center,

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and then another one called a FONT,

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which is going to be set to this tuple.

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And then I can use these constants down here,

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so align = ALIGNMENT, font = FONT. That way,

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when I decide that I want to change something about the alignment or the font,

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so for example instead of Arial,

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I might go for something that is a little bit more video-gamey

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sort of font like courier,

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then I don't have to dig through the body of my program to find out where it was

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defined. I can just look at the top

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which contains all the constants and then fix it right here. That shouldn't have

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changed any of the functionality. It's just made our scoreboard look a bit more

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video-gamey, and you can see how it works perfectly.