1 00:00:00,180 --> 00:00:02,160 All right. So just as previously, 2 00:00:02,220 --> 00:00:07,220 we've split up this large problem of building the game into five smaller 3 00:00:07,320 --> 00:00:09,090 sub-parts. Firstly, 4 00:00:09,120 --> 00:00:13,140 moving the turtle, controlling it with the keypress, creating and moving the 5 00:00:13,140 --> 00:00:15,540 cars automatically across the screen, 6 00:00:15,810 --> 00:00:19,740 detecting a collision with the car and detecting when the turtle reaches the 7 00:00:19,740 --> 00:00:21,300 other side. Finally, 8 00:00:21,300 --> 00:00:24,510 we create a scoreboard that keeps track of which level we're on 9 00:00:24,750 --> 00:00:27,090 and also that shows game over at the end. 10 00:00:27,810 --> 00:00:31,710 So the first step is to move the turtle using a keypress. 11 00:00:32,070 --> 00:00:36,480 The turtle can only go forwards, and every time we hit the Up key 12 00:00:36,690 --> 00:00:41,580 the turtle moves forward by a set amount until it reaches the other side of the 13 00:00:41,580 --> 00:00:45,000 screen. This is the first thing that we're going to tackle. Now, 14 00:00:45,030 --> 00:00:48,180 because this is related to the functionality of the player, 15 00:00:48,510 --> 00:00:51,870 let's go ahead and create this inside the player class. 16 00:00:52,800 --> 00:00:54,420 I'm going to delete that pass 17 00:00:54,540 --> 00:00:59,340 and I'm also going to import the turtle class from the turtle module. 18 00:01:00,090 --> 00:01:04,170 Now, our player is going to inherit from this turtle class. 19 00:01:04,709 --> 00:01:06,720 So inside our init, 20 00:01:06,930 --> 00:01:10,830 we're going to need to add the super.init 21 00:01:10,860 --> 00:01:13,860 or you can add it automatically using the light bulb. 22 00:01:14,460 --> 00:01:19,460 So now this player class can do everything that a turtle class can do and we can 23 00:01:20,490 --> 00:01:21,870 make it do even more. 24 00:01:22,830 --> 00:01:27,630 The first thing we're going to do is we're going to set the shape of our player 25 00:01:27,960 --> 00:01:30,210 and we're gonna set it to a turtle. 26 00:01:30,810 --> 00:01:34,770 The next thing we're going to do is we're going to call penup so that this 27 00:01:34,770 --> 00:01:39,330 turtle just remains a shape and it doesn't draw. Finally, 28 00:01:39,360 --> 00:01:43,470 we need to get it to the starting position and get it to face North. 29 00:01:43,950 --> 00:01:48,950 We can do that by setting self.goto and then we can set it to go to the 30 00:01:50,370 --> 00:01:51,660 starting position, 31 00:01:52,350 --> 00:01:57,350 which you can see is a tuple because it's enclosed inside parentheses and you've 32 00:01:59,040 --> 00:02:03,300 got values separated by a comma. Finally, 33 00:02:03,330 --> 00:02:08,330 we're going to set the heading of our turtle so that it faces North, 34 00:02:09,300 --> 00:02:11,220 which is 90 degrees. 35 00:02:11,880 --> 00:02:16,800 So now all we have to do is go back into our main.py, 36 00:02:17,400 --> 00:02:19,410 after we've set up our screen, 37 00:02:19,650 --> 00:02:23,880 let's go ahead and create a new player from the player class. 38 00:02:25,290 --> 00:02:27,360 Let's go ahead and run this code. 39 00:02:28,160 --> 00:02:28,993 ... 40 00:02:30,650 --> 00:02:35,650 And you can see that we've got our little turtle showing up here at the center 41 00:02:37,400 --> 00:02:40,850 of the bottom of the screen and it's facing North. 42 00:02:42,380 --> 00:02:47,270 So now the next thing we need to do is to get that turtle to move upwards 43 00:02:47,540 --> 00:02:49,460 every time we hit the Up key. 44 00:02:50,060 --> 00:02:53,450 That means we're going to need to get our screen to 45 00:02:53,480 --> 00:02:57,620 listen for events. After calling screen.listen, 46 00:02:57,680 --> 00:03:02,680 we're going to get the screen to listen to a keystroke. So we can use onkey to 47 00:03:04,720 --> 00:03:08,080 set the Up key as the key to listen to. 48 00:03:08,650 --> 00:03:13,390 And then when that happens, then we're going to call player. 49 00:03:14,110 --> 00:03:19,110 go_up. And remember that when we're calling methods inside the listener, 50 00:03:20,320 --> 00:03:24,970 we don't want to add the parentheses because this will trigger it at the point 51 00:03:25,030 --> 00:03:28,900 where it evaluates this line of code. Instead, 52 00:03:28,930 --> 00:03:33,550 we want to trigger this function only when this Up key is detected. 53 00:03:34,240 --> 00:03:39,240 So now all that's left to do is to go into our player.py and define that 54 00:03:40,000 --> 00:03:41,680 function go_up. 55 00:03:42,850 --> 00:03:46,630 So how can we move our turtle up? Well, 56 00:03:46,630 --> 00:03:50,080 we can get our turtle so self, 57 00:03:50,410 --> 00:03:53,710 and then we can get it to move forwards by a distance. 58 00:03:54,280 --> 00:03:58,930 And the distance is going to be the move distance that's set in this constant 59 00:03:58,930 --> 00:04:03,070 here. This means that later on when we want to change the move distance 60 00:04:03,070 --> 00:04:06,970 if we want it to go further each time, we can just edit it at the top of the 61 00:04:06,970 --> 00:04:09,130 file instead of digging through the code. 62 00:04:10,540 --> 00:04:14,350 Now let's run our code again and let's just make sure that it works. 63 00:04:14,830 --> 00:04:16,660 So now every time I hit the Up key 64 00:04:16,690 --> 00:04:21,690 my turtle moves up and it keeps on going until it reaches the other side of the 65 00:04:21,730 --> 00:04:26,500 screen. So that's the first step completed. Now, 66 00:04:26,530 --> 00:04:28,990 if you think you can complete the next step by yourself, 67 00:04:29,290 --> 00:04:34,290 then head back to that list of problems broken down and see if you can tackle 68 00:04:34,390 --> 00:04:39,010 the next one by yourself. If you can't or if you need some extra help, 69 00:04:39,130 --> 00:04:42,460 then you can always come back to the videos and I'll walk you through the steps 70 00:04:42,490 --> 00:04:43,120 one by one.