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So to start off,

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go ahead and create a new project called snake_game in PyCharm.

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And then inside this project, we're going to create a new main.py file.

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And inside our file, we're going to need our normal imports.

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So I'm going to say from turtle import the screen class and also the turtle

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class. Now,

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the first thing we're going to do is we're going to create a new screen,

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which is basically going to be the window that shows up.

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And then we're going to set up our screen so that it is 600 by 600.

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So the width is going to be 600 pixels and the height is also going to be 600

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pixels. And notice how I'm using these keyword arguments

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so that it's a little bit clearer to the next person looking at this code

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what's actually happening here. Now,

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the other thing I want to change is the screen's background color.

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So there's a method called bgcolor and inside here

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we're going to write the text black so that we end up with a black screen.

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Now,

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another thing that you might not have seen before is how to set the title of

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the window that shows up. And we do that through a method called title,

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and you can name your program here. So I'm going to call it 'My Snake Game',

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but you can of course call it whatever it is you want. Now finally,

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at the very bottom of the file, I'm going to say screen.exitonclick.

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So this way, when I actually run it, it doesn't just disappear straight away

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and it waits for me and I can look at what's actually happened so far.

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So I'm going to click run and then select my main file.

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And once it pops up,

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this is what you should see, a 600 by 600 square window

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and then at the top of the window, you'll see the name of your program,

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which is My Snake Game. And the background is now black.

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Now that we've set up our screen,

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we're ready to tackle the first of our seven steps,

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which is to create a snake body.

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And we're going to create three squares

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which are each going to be turtles,

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and they're going to be lined up next to each other along the horizontal axis.

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So let's think about this. When we create a new turtle,

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it has a dimension of 20 pixels wide by 20 pixels tall.

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And if we want three of them lined up next to each other,

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then we have to think about how we create their coordinates. As a challenge,

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I want you to think about how we can create this. Here

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we have three separate squares

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which are each a turtle object and they're shaped like a square and they have a

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white color. Now, they're positioned

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so that the first one is (0, 0),

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the next one is 20 pixels to the left and the next one is again

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20 pixels to the left so that none of the squares overlap with each other,

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but there's also no gaps. So it looks like a whole snake.

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This is your challenge

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and you might have to think about a few of the things that we've done before in

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order to achieve this. So browse the documentation,

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look back to the previous code that you've written and see if you can solve this

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challenge. Pause the video now.

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Alright.

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So the first thing we're going to need to do is to create some sort of turtle,

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right?

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So let's call this segment_1 and this is going to be a new turtle.

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And remember that when we initialize the turtle,

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we can already specify the shape.

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So we can either say shape = "square",

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or simply just leave it as square. So now at this point,

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we should end up with a square turtle, but because it's black,

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when we run the code, we won't actually see it on screen.

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So let's change this segment color to white.

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And all we have to do is write the word for the color

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and now when we rerun our code,

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you can see a white square at the center,

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which is at position (0, 0).

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Now the next step is to create our other two white squares.

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So let's go ahead and copy these bits of code,

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and I'm going to create three of them in total.

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So segment_2 and segment_3.

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Now here, we're going to create the same thing,

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but we obviously have to change the positioning because otherwise we end up with

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three squares all on top of each other,

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and we can only see one square because this is a 2-D image.

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So let's go ahead and make segment_2 go to a different position.

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So the first thing we have to specify is the X,

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which you remember is the horizontal axis here.

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And if we want another square to the left of it,

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then we're going to have to go to -20 from zero.

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That way it will be shifted to the left by 20 pixels.

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Let's say go to -20

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and then the Y-axis is going to be zero because it's not going to move up or

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down.

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Now let's take a look at the result of this and you can see we've now got two

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squares lining side by side,

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but the third square is still at the center.

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So the third segment is going to be shifted a further 20 pixels.

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This is centered on (0, 0), this is at (-20, 0),

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then this has to be at (-40, 0).

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So let's tell our segment_3 to go to (-40, 0).

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And this is what we see.

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Did you manage to achieve this or did you do it in a different way? Now,

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a much easier way of creating this would have been to use a for loop.

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For example, we

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could have created a list of

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starting positions

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and this could contain some tuples.

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So we know that in order to specify where the segment should go to,

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we have to provide a tuple, which is a X and a Y value.

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And we know that we can create a tuple just by using a set of parentheses and

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then adding values in there, separated by commas.

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So if the first segment has to be at the center, then that's going to be 

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(0, 0), and then the second piece is going to be at (-20, 0),

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and the third piece is going to be at (-40, 0).

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Now we can create

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a for loop. So for

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position in starting_positions,

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let's loop through this list and create a new segment for each of those

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positions. So now we're going to create a new segment

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that's a square turtle, that's going to be white,

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and we're going to get the segment to go to the position that we're currently

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looping on. Now we can delete all of that code

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and when we run our code again, you can see we have the same effect.

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We have all three pieces. So if you can't remember how tuples work,

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be sure to go back to the lessons on tuples in Day 18,

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where we talked about how to write them and how they work.

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But that completes our first step.

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We've managed to create three segments that will comprise our snake

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and in the next lesson,

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we're going to figure out how to get our snake to start moving by itself on the

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screen. So for all of that and more, I'll see you on the next lesson.