WEBVTT 0 00:00.330 --> 00:05.250 So in the last lesson, we saw how to create a turtle that does a random walk. 1 00:05.760 --> 00:07.020 Now in this lesson, 2 00:07.080 --> 00:12.080 I want to show you how you can create a random color for your turtle drawing 3 00:12.540 --> 00:16.890 rather than just using the named colors and then picking a random one out of the 4 00:16.890 --> 00:21.390 list. When you take a look at the pen color of the turtle, 5 00:21.810 --> 00:26.810 you can see that you can use a color string such as what we've been doing using 6 00:26.940 --> 00:30.420 red, yellow, or a hex string that represents the color, 7 00:31.020 --> 00:33.690 or we can use a RGB color. 8 00:34.170 --> 00:39.170 And the RGB color is going to be represented by a tuple of different amounts of 9 00:39.510 --> 00:43.560 red, green, and blue. So what exactly is a tuple? 10 00:44.310 --> 00:44.760 Well, 11 00:44.760 --> 00:49.760 a tuple is a data type in Python and it looks like this. 12 00:50.130 --> 00:52.830 It has round brackets around it 13 00:53.190 --> 00:56.970 and then each of the items inside are separated by a comma. 14 00:57.570 --> 00:59.970 So does this remind you of another data type? 15 01:00.600 --> 01:04.110 Does it not look a little bit like a list? Well, 16 01:04.110 --> 01:08.880 indeed a tuple is very similar to a list. Each of the items that go into the 17 01:08.880 --> 01:10.260 tuple are ordered. 18 01:10.740 --> 01:15.720 So let's pull up my Python console here and let's create my tuple 19 01:17.130 --> 01:21.060 which is denoted by a set of round parentheses 20 01:21.450 --> 01:25.410 and then let's put in three items, 1, 3, and 8, 21 01:26.010 --> 01:28.320 and there we have created a new tuple. 22 01:28.950 --> 01:32.370 Now in order to get hold of any of those items in there, 23 01:32.460 --> 01:36.540 I can write the name of the variable and then using square brackets 24 01:36.570 --> 01:38.460 I can access the index. 25 01:38.730 --> 01:43.710 So 1 is going to be at position zero, 3 is going to be at position one and 26 01:43.740 --> 01:47.220 8 is going to be at position two. So if I hit enter on this, 27 01:47.280 --> 01:49.350 then you can see that's going to be equal to 8. 28 01:50.820 --> 01:52.860 And if you click this drop down on the right, 29 01:52.890 --> 01:56.700 you can see the same representation; position 0, 1, 2, 30 01:57.060 --> 02:00.510 and those pieces of data and the total length is three. 31 02:01.110 --> 02:05.760 So at this point you might be asking yourself, well, I already know about lists, 32 02:05.820 --> 02:10.320 so why do I need to know about tuples? What's the difference anyways? Well, 33 02:10.350 --> 02:14.220 a tuple is going to be carved in stone 34 02:14.460 --> 02:18.390 so you can't change the values like you can with lists. 35 02:19.500 --> 02:22.020 For example, if I wanted to say 36 02:22.020 --> 02:26.220 get hold of my tuple and instead of the 8 at position two, 37 02:26.610 --> 02:30.630 I want to change it to 12. Now, if I go ahead and hit enter, 38 02:30.660 --> 02:34.350 you can see I get a error and this is a type error. 39 02:34.890 --> 02:39.390 This particular type, tuple, does not support item assignment. 40 02:39.600 --> 02:42.720 So I can't just change it willingly like this. 41 02:43.290 --> 02:46.380 And I also can't remove items from the tuple, 42 02:46.620 --> 02:51.330 I can't change it in any way. Once you've created your tuple 43 02:51.360 --> 02:56.360 you can consider it as carved in stone and it is what we call immutable. 44 02:57.150 --> 03:01.900 It cannot be changed. So why would you use a tuple then? 45 03:02.620 --> 03:03.880 Well, think about the times 46 03:04.150 --> 03:07.990 like say if you're creating a color scheme for your website or are you creating 47 03:07.990 --> 03:12.220 some sort of list that you want to stay constant and you don't want somebody to 48 03:12.220 --> 03:16.360 accidentally change it or accidentally mess it up, well, 49 03:16.360 --> 03:18.610 then you might want to consider using a tuple. 50 03:20.050 --> 03:23.800 And if you find yourself creating a tuple and then realizing, Oh, 51 03:23.830 --> 03:26.020 actually I need to change it well, 52 03:26.020 --> 03:29.650 then you can simply put your tuple inside a list like this, 53 03:30.010 --> 03:32.800 and you can actually convert it into a list. 54 03:34.150 --> 03:36.010 Coming back to our documentation, 55 03:36.400 --> 03:41.400 the color is represented by a tuple because if you define a color, 56 03:41.680 --> 03:43.330 you're unlikely to change it. 57 03:44.020 --> 03:46.870 And then we have a r, g, and b, 58 03:46.960 --> 03:50.380 which is in the range between zero and the color mode. 59 03:50.860 --> 03:55.860 So the mode can be between 0 and 1 or 0 and 255. In the course resources, 60 03:58.030 --> 04:01.810 I've linked to this really handy RGB calculator tool, 61 04:02.290 --> 04:06.190 which demonstrates how RGB colors work so perfectly. 62 04:06.610 --> 04:10.060 You can see that if we have zero amount of red, zero amounts of green, 63 04:10.090 --> 04:11.920 zero amounts of blue, we get black. 64 04:12.430 --> 04:17.430 But if we mix different amounts of red and different amounts of green and 65 04:18.670 --> 04:22.030 different amounts of blue, then we can get all of the colors in the rainbow. 66 04:22.360 --> 04:26.020 The three primary colors can create any color that you dream of. 67 04:26.620 --> 04:29.110 And each of these sliders, 68 04:29.140 --> 04:34.000 you can see, goes from 0 all the way up to 255. 69 04:34.570 --> 04:38.230 So more red, more green or more blue. 70 04:39.220 --> 04:42.730 And this is what the RGB color ends up looking like. 71 04:43.930 --> 04:48.790 I find it easier to think about the range between 0 and 255. 72 04:49.330 --> 04:50.200 So in turtle, 73 04:50.200 --> 04:54.880 we actually have to change the color mode to 255. 74 04:55.510 --> 04:57.340 So to do this, it's a little bit tricky 75 04:57.370 --> 04:59.920 which is why I didn't want to put this as part of the challenge. 76 05:00.310 --> 05:04.750 But we have to tap into the actual turtle module and not the turtle object, 77 05:04.990 --> 05:09.910 and then change the color mode for that module. Back in our code, 78 05:09.940 --> 05:12.490 we can tap into our turtle module 79 05:12.820 --> 05:15.910 which is known as 't' in our code. 80 05:17.080 --> 05:22.080 And then we can tap into the color mode to make it go from 0 to 255. 81 05:24.610 --> 05:29.590 So now that we've changed the color mode, we can now create a random color. 82 05:30.040 --> 05:33.280 So let's get rid of this list of colors. Instead, 83 05:33.280 --> 05:36.880 I'm going to create a new function called a random_color, 84 05:37.960 --> 05:42.960 and this function is going to return a random color using RGB. 85 05:44.440 --> 05:47.410 So let's first create a random red. 86 05:48.280 --> 05:53.280 So we use the random module and then use the randint and then generate a number 87 05:53.620 --> 05:56.740 between 0 and 255. 88 05:57.710 --> 06:02.420 And then we can repeat this process for the other two color spaces, 89 06:02.750 --> 06:05.900 so green and for blue. 90 06:06.920 --> 06:08.930 Now we've got three random numbers, 91 06:08.960 --> 06:11.480 one each representing each of the color spaces, 92 06:11.840 --> 06:15.590 and then we can generate our tuple. Here's the challenge for you. 93 06:15.950 --> 06:18.290 See if you can return from this function 94 06:18.350 --> 06:23.350 a tuple that consists of the three random integers, r, g and b, 95 06:24.710 --> 06:29.710 and then use that random color to color the turtle drawing instead of this broken 96 06:30.920 --> 06:34.070 code which relied on that previous list of colors. 97 06:34.610 --> 06:37.220 Pause the video and see if you can complete this challenge. 98 06:40.150 --> 06:42.460 All right. So we know that to create a tuple 99 06:42.460 --> 06:45.460 we need a set of round brackets or parentheses, 100 06:45.940 --> 06:48.610 and then we're going to put each of these in order, 101 06:48.610 --> 06:53.380 so r, g and b. So here's our tuple created, 102 06:53.410 --> 06:56.860 and this is basically our new random color. 103 06:57.460 --> 07:02.460 And then this function is going to return that random color as the output. 104 07:03.850 --> 07:08.350 So now instead of using random.choice and using that previous list, 105 07:08.860 --> 07:11.770 all we have to do is get hold of a random color 106 07:12.160 --> 07:16.840 that's going to be outputted from this function and then use it to color Tim's 107 07:16.840 --> 07:19.780 drawing. So let's run this code again, 108 07:20.320 --> 07:23.380 and you should be able to see that in this random walk, 109 07:23.500 --> 07:25.780 the color is completely random. 110 07:26.110 --> 07:31.110 Pretty much every single turn is going to draw something completely different in 111 07:31.540 --> 07:32.373 terms of color. 112 07:33.190 --> 07:38.080 And this is achieved by learning a little bit about how colors work and how we 113 07:38.080 --> 07:41.860 can generate them using the random RGB colors.