WEBVTT 0 00:00.180 --> 00:02.160 All right. So just as previously, 1 00:02.220 --> 00:07.220 we've split up this large problem of building the game into five smaller 2 00:07.320 --> 00:09.090 sub-parts. Firstly, 3 00:09.120 --> 00:13.140 moving the turtle, controlling it with the keypress, creating and moving the 4 00:13.140 --> 00:15.540 cars automatically across the screen, 5 00:15.810 --> 00:19.740 detecting a collision with the car and detecting when the turtle reaches the 6 00:19.740 --> 00:21.300 other side. Finally, 7 00:21.300 --> 00:24.510 we create a scoreboard that keeps track of which level we're on 8 00:24.750 --> 00:27.090 and also that shows game over at the end. 9 00:27.810 --> 00:31.710 So the first step is to move the turtle using a keypress. 10 00:32.070 --> 00:36.480 The turtle can only go forwards, and every time we hit the Up key 11 00:36.690 --> 00:41.580 the turtle moves forward by a set amount until it reaches the other side of the 12 00:41.580 --> 00:45.000 screen. This is the first thing that we're going to tackle. Now, 13 00:45.030 --> 00:48.180 because this is related to the functionality of the player, 14 00:48.510 --> 00:51.870 let's go ahead and create this inside the player class. 15 00:52.800 --> 00:54.420 I'm going to delete that pass 16 00:54.540 --> 00:59.340 and I'm also going to import the turtle class from the turtle module. 17 01:00.090 --> 01:04.170 Now, our player is going to inherit from this turtle class. 18 01:04.710 --> 01:06.720 So inside our init, 19 01:06.930 --> 01:10.830 we're going to need to add the super.init 20 01:10.860 --> 01:13.860 or you can add it automatically using the light bulb. 21 01:14.460 --> 01:19.460 So now this player class can do everything that a turtle class can do and we can 22 01:20.490 --> 01:21.870 make it do even more. 23 01:22.830 --> 01:27.630 The first thing we're going to do is we're going to set the shape of our player 24 01:27.960 --> 01:30.210 and we're gonna set it to a turtle. 25 01:30.810 --> 01:34.770 The next thing we're going to do is we're going to call penup so that this 26 01:34.770 --> 01:39.330 turtle just remains a shape and it doesn't draw. Finally, 27 01:39.360 --> 01:43.470 we need to get it to the starting position and get it to face North. 28 01:43.950 --> 01:48.950 We can do that by setting self.goto and then we can set it to go to the 29 01:50.370 --> 01:51.660 starting position, 30 01:52.350 --> 01:57.350 which you can see is a tuple because it's enclosed inside parentheses and you've 31 01:59.040 --> 02:03.300 got values separated by a comma. Finally, 32 02:03.330 --> 02:08.330 we're going to set the heading of our turtle so that it faces North, 33 02:09.300 --> 02:11.220 which is 90 degrees. 34 02:11.880 --> 02:16.800 So now all we have to do is go back into our main.py, 35 02:17.400 --> 02:19.410 after we've set up our screen, 36 02:19.650 --> 02:23.880 let's go ahead and create a new player from the player class. 37 02:25.290 --> 02:27.360 Let's go ahead and run this code. 38 02:28.160 --> 02:28.993 ... 39 02:30.650 --> 02:35.650 And you can see that we've got our little turtle showing up here at the center 40 02:37.400 --> 02:40.850 of the bottom of the screen and it's facing North. 41 02:42.380 --> 02:47.270 So now the next thing we need to do is to get that turtle to move upwards 42 02:47.540 --> 02:49.460 every time we hit the Up key. 43 02:50.060 --> 02:53.450 That means we're going to need to get our screen to 44 02:53.480 --> 02:57.620 listen for events. After calling screen.listen, 45 02:57.680 --> 03:02.680 we're going to get the screen to listen to a keystroke. So we can use onkey to 46 03:04.720 --> 03:08.080 set the Up key as the key to listen to. 47 03:08.650 --> 03:13.390 And then when that happens, then we're going to call player. 48 03:14.110 --> 03:19.110 go_up. And remember that when we're calling methods inside the listener, 49 03:20.320 --> 03:24.970 we don't want to add the parentheses because this will trigger it at the point 50 03:25.030 --> 03:28.900 where it evaluates this line of code. Instead, 51 03:28.930 --> 03:33.550 we want to trigger this function only when this Up key is detected. 52 03:34.240 --> 03:39.240 So now all that's left to do is to go into our player.py and define that 53 03:40.000 --> 03:41.680 function go_up. 54 03:42.850 --> 03:46.630 So how can we move our turtle up? Well, 55 03:46.630 --> 03:50.080 we can get our turtle so self, 56 03:50.410 --> 03:53.710 and then we can get it to move forwards by a distance. 57 03:54.280 --> 03:58.930 And the distance is going to be the move distance that's set in this constant 58 03:58.930 --> 04:03.070 here. This means that later on when we want to change the move distance 59 04:03.070 --> 04:06.970 if we want it to go further each time, we can just edit it at the top of the 60 04:06.970 --> 04:09.130 file instead of digging through the code. 61 04:10.540 --> 04:14.350 Now let's run our code again and let's just make sure that it works. 62 04:14.830 --> 04:16.660 So now every time I hit the Up key 63 04:16.690 --> 04:21.690 my turtle moves up and it keeps on going until it reaches the other side of the 64 04:21.730 --> 04:26.500 screen. So that's the first step completed. Now, 65 04:26.530 --> 04:28.990 if you think you can complete the next step by yourself, 66 04:29.290 --> 04:34.290 then head back to that list of problems broken down and see if you can tackle 67 04:34.390 --> 04:39.010 the next one by yourself. If you can't or if you need some extra help, 68 04:39.130 --> 04:42.460 then you can always come back to the videos and I'll walk you through the steps 69 04:42.490 --> 04:43.120 one by one.