WEBVTT 00:00.050 --> 00:05.510 All right, guys, so now that we've loaded up all the knowledge that we need into our brains, it's 00:05.510 --> 00:08.870 time to tackle the final project of the day. 00:08.870 --> 00:14.360 And as I showed you in the beginning of the day, it's a rock, paper, scissors game that we can play 00:14.360 --> 00:15.590 with the computer. 00:15.680 --> 00:22.130 So the game starts out by asking you to type zero for rock, one for paper or two for scissors. 00:22.130 --> 00:25.070 So let's go ahead and type two for scissors. 00:25.100 --> 00:29.900 And then it's going to show you a graphic of your choice scissors. 00:29.900 --> 00:33.440 And then the choice the computer made which is rock. 00:33.470 --> 00:35.600 And of course rock beats scissors. 00:35.600 --> 00:37.040 So you lose. 00:37.070 --> 00:44.720 What this game boils down to is some way of randomly making a choice between rock, paper, or scissors, 00:44.720 --> 00:51.080 and then comparing that choice that the computer randomly generated against your choice. 00:51.080 --> 00:57.050 And then based on the rules of rock, paper and scissors, determining whether if you won, you lost, 00:57.050 --> 01:00.050 or whether if you had a drawer. 01:00.710 --> 01:08.060 While I was looking around, I actually came across the world Rock paper Scissors Association and they 01:08.060 --> 01:12.800 have the official rules, um, listed of rock, paper and scissors. 01:12.830 --> 01:17.240 If you're not familiar with this game, it might be worth checking out this website. 01:17.270 --> 01:20.180 Here are the three shapes of rock, paper and scissors. 01:20.180 --> 01:24.650 And then the rules are that rock wins against scissors. 01:24.680 --> 01:28.670 Scissors wins against paper and paper wins against rock. 01:29.390 --> 01:35.930 Now you'll notice that in the starting project, I've already got the Ascii art for rock, paper and 01:35.930 --> 01:39.950 scissors in here, and they each saved to a variable. 01:39.950 --> 01:47.300 So what that means is that you can start out by just having a go at printing out, let's say, a rock, 01:47.480 --> 01:49.910 and remember that these are variable names. 01:49.910 --> 01:53.420 They're not strings, so they don't need the double quotes around them. 01:53.420 --> 02:00.540 So let's run that and you can see what we get printed is the particular Ascii art that I chose in my 02:00.540 --> 02:01.560 print statement. 02:01.890 --> 02:04.830 So this is already yours. 02:04.830 --> 02:11.460 But as you'll notice, there's no other logic that I've provided you, and you are going to rely on 02:11.460 --> 02:16.980 what you've learned in the previous days and most importantly, what you've learned in today's lessons 02:16.980 --> 02:19.080 to be able to complete this challenge. 02:19.080 --> 02:25.440 And it's worth comparing the outcome against the game of rock, paper, scissors that I'll link to. 02:25.770 --> 02:30.930 There's a couple of things to think about, namely, how are you going to decide who won or who lost? 02:30.960 --> 02:38.010 How are you going to get the computer to choose a random shape rock, paper or scissors and how you 02:38.010 --> 02:43.440 actually get this game to work in the same way that is demoed in this final version? 02:43.950 --> 02:51.780 I'm going to go quiet now, and I'm going to let you pause the video, and I want you to spend at least 02:51.780 --> 02:53.910 10 or 15 minutes working on this. 02:53.910 --> 02:59.100 And if you get stuck, just try some things out or maybe watch some of the previous videos in the day 02:59.100 --> 03:01.620 and just try to give it your best. 03:01.620 --> 03:04.140 Go and do a lot of struggling. 03:04.170 --> 03:08.850 Hopefully you're going to succeed, and once you're done, head back over here and I'll go through the 03:08.850 --> 03:09.840 solution with you. 03:09.840 --> 03:11.400 So pause the video now. 03:11.790 --> 03:14.940 A3 all right. 03:14.940 --> 03:17.550 So we know that we've got all of this Ascii art. 03:17.550 --> 03:24.180 But for the moment I'm just going to start off by pinning down the basic logic of this game. 03:24.180 --> 03:30.660 And it's really helpful for you as well if you start thinking about breaking down the larger problem, 03:30.660 --> 03:36.720 which is making the rock, paper, scissors game into smaller problems that you can solve, like generating 03:36.720 --> 03:39.060 a random number between 1 and 3. 03:39.060 --> 03:42.510 So we have some sort of proxy for rock, paper and scissors. 03:42.510 --> 03:45.450 And then maybe thinking about putting down the logic. 03:45.450 --> 03:51.330 Well, if the computer chose scissors and I chose paper, then I'm going to lose. 03:51.330 --> 03:56.170 Or if the computer chose rock and I chose paper, then I'm going to win. 03:56.170 --> 04:02.770 And putting that down on a flow chart using Draw.io or something like that can make this challenge a 04:02.770 --> 04:04.450 lot easier as well. 04:05.140 --> 04:11.170 But without further ado, the first thing I need to do is to produce a user choice. 04:11.200 --> 04:17.140 Now this is going to be the one that the user chose when they typed in a value. 04:17.170 --> 04:21.940 And in order to get the value from them, I'm going to need to use a input. 04:21.970 --> 04:29.350 And inside the input I'm going to put the following prompt asking the user what do you choose? 04:29.380 --> 04:33.280 Type zero for rock, one for paper or two for scissors. 04:33.310 --> 04:39.940 Now once I get hold of this input, hopefully if the user is following my instructions, they're going 04:39.940 --> 04:43.720 to type some sort of number, either 0 or 1 or two. 04:43.750 --> 04:49.960 Now that I've gotten hold of what the user wants to choose, the next thing to do is figure out what 04:49.960 --> 04:51.640 the computer is going to choose. 04:51.670 --> 04:58.010 So I'm going to make another variable called computer choice and I'm going to generate a random number. 04:58.040 --> 05:02.210 So to do that remember we have to import the random module. 05:03.500 --> 05:11.720 And then we can start using it to generate random whole numbers by using random dot randint. 05:11.720 --> 05:16.520 And then the range is going to be between 0 and 2. 05:16.550 --> 05:18.950 Because this is what I asked the user to do. 05:18.980 --> 05:22.160 Type zero for rock, one for paper, two for scissors. 05:22.160 --> 05:27.020 So the computer is also going to choose between zero, 1 or 2. 05:27.620 --> 05:33.680 Now that I've got the computer choice, I'm actually going to just print it out for now instead of printing 05:33.680 --> 05:37.610 out the actual shape, I'm just going to print out the number. 05:37.610 --> 05:40.700 So computer chose. 05:40.700 --> 05:43.790 And then let's go ahead and add a F string. 05:45.620 --> 05:49.460 And of course that requires the f in front of the string. 05:49.760 --> 05:55.160 So now if we just play the game as it is, remember that testing your app while you're developing it 05:55.160 --> 05:57.020 is really, really good practice. 05:57.050 --> 06:02.900 It picks up on the bugs that you make along the way, instead of waiting until the end when you've done 06:02.900 --> 06:07.610 everything and then it doesn't work, and you have to untangle all of the lines of code. 06:07.790 --> 06:13.010 At this point, I've already realized that it's actually not so great getting the user to type on this 06:13.010 --> 06:13.730 line. 06:14.150 --> 06:19.070 What I would much rather is to start a new line for them to type their answer on. 06:19.100 --> 06:22.850 So if I run the code again, then it should look a bit like this. 06:22.850 --> 06:24.140 My prompt is now here. 06:24.140 --> 06:27.050 So I'm going to choose zero for rock. 06:27.050 --> 06:30.860 And then it tells me that computer also chose zero. 06:30.860 --> 06:33.020 So in this case this would be a draw. 06:33.020 --> 06:38.540 But if I played this game again, you can see that the computer is probably going to choose something 06:38.540 --> 06:39.170 different. 06:39.170 --> 06:40.640 So I chose rock again. 06:40.670 --> 06:43.250 The computer chose one, which is paper. 06:43.460 --> 06:51.710 So now we can start thinking about how do we compare these two choices, and how can we define the logic 06:51.710 --> 06:53.750 of rock, paper, scissors. 06:53.780 --> 07:01.250 So I know that paper beats rock, scissors beats paper, and rock will beat scissors. 07:01.250 --> 07:10.190 So if zero is rock, one is paper and two is scissors, then two beats one and one beats zero. 07:10.190 --> 07:16.790 So that's very simple for us to check in terms of using if statements. 07:16.820 --> 07:17.030 Right. 07:17.060 --> 07:19.010 We could simply just check. 07:19.010 --> 07:29.480 Well, if the computer choice is greater than the user choice, well then this probably means that the 07:29.480 --> 07:31.490 computer wins. 07:32.300 --> 07:36.050 But this is not true in all cases, right? 07:36.050 --> 07:43.880 Because if the computer chose two for scissors and the user chose zero for rock, then the user should 07:43.880 --> 07:46.130 win rather than the computer winning. 07:46.130 --> 07:51.080 So we actually have some exceptions to this rule. 07:51.410 --> 07:57.740 How can we catch the exceptions before we go down to this level of generalization? 07:57.770 --> 08:00.920 Well, we could, instead of using this as an. 08:00.950 --> 08:09.200 If we use this as an Elif and we create another if statement which says, well, if the user choice 08:09.230 --> 08:11.120 is equal to zero. 08:11.120 --> 08:18.260 So if the user chose rock and the computer choice was two. 08:18.290 --> 08:23.270 Well then this means that in this case the user actually wins. 08:24.500 --> 08:29.960 Now, if we're thinking from the perspective of the user when they're playing this game, then they 08:29.960 --> 08:33.440 don't really care if the computer won or the user won. 08:33.440 --> 08:36.470 They want to know did they win or did they lose. 08:36.470 --> 08:38.990 So let's change this wording a little bit. 08:39.020 --> 08:44.060 We'll say instead of user wins we'll say you win. 08:44.510 --> 08:49.850 And if the computer wins then we'll say you lose. 08:49.850 --> 08:49.860 News. 08:50.160 --> 08:54.960 So now if we run our program and test it out. 08:54.960 --> 08:58.470 So let's say I'm going to type zero for rock. 08:58.680 --> 09:00.600 But we actually get an error. 09:00.600 --> 09:08.940 It tells us that the greater than comparison is not supported between instances of int and string. 09:08.940 --> 09:10.170 What's going on here. 09:10.170 --> 09:14.760 Well remember that we get our input as a number. 09:14.760 --> 09:19.020 But the input is always going to be a string. 09:19.020 --> 09:20.820 So we want this to be a number. 09:20.820 --> 09:24.210 Then we're going to have to wrap it inside an int. 09:24.210 --> 09:27.210 So now we turn it into a whole number. 09:27.810 --> 09:29.820 Now this might be a good point to address. 09:29.820 --> 09:34.170 Well what should happen if they typed something that wasn't zero 1 or 2? 09:34.200 --> 09:36.090 What if they typed 34? 09:36.120 --> 09:39.090 Well then naturally they should probably lose, right? 09:39.090 --> 09:43.200 So we can add an else statement addressing this situation. 09:43.200 --> 09:47.160 So we could say else we just print. 09:47.190 --> 09:50.520 You typed an invalid number. 09:50.730 --> 09:51.930 You lose. 09:52.920 --> 09:53.460 Cool. 09:53.460 --> 09:54.840 So that sorts that out. 09:54.870 --> 09:59.100 Now let's run our code again and see if it works. 09:59.130 --> 09:59.910 What do you choose? 09:59.940 --> 10:01.050 Type zero for ROC. 10:01.080 --> 10:02.640 I'm going to choose ROC again. 10:02.670 --> 10:08.130 Computer chose zero and it tells me that you typed an invalid number. 10:08.640 --> 10:11.910 Well, actually zero is not an invalid number. 10:11.910 --> 10:13.470 So what's going on here? 10:13.500 --> 10:17.250 Well, it's because it didn't fit this criteria. 10:17.340 --> 10:24.900 So I had zero, computer had zero, and it didn't fit this criteria because zero is not greater than 10:24.930 --> 10:25.710 zero. 10:25.710 --> 10:29.940 So it basically defaulted to the final else statement. 10:30.240 --> 10:34.620 But what's actually happening here is that that was a draw. 10:34.650 --> 10:35.970 Computer chose ROC. 10:36.000 --> 10:36.930 I chose ROC. 10:36.960 --> 10:42.090 That's a draw in the official rules of Rock, paper, scissors. 10:42.240 --> 10:44.610 So how do I catch that? 10:44.610 --> 10:51.550 Well, I could create another Elif statement which says, well, if the computer choice is equal to 10:51.580 --> 10:52.690 the user choice. 10:52.720 --> 10:54.910 Well, then we're going to print. 10:55.270 --> 10:56.950 It's a draw. 10:57.820 --> 11:03.580 Now let's test our app again and see if there are any other situations where our code is not behaving 11:03.580 --> 11:04.600 properly. 11:04.780 --> 11:06.880 I'm going to choose rock again. 11:06.910 --> 11:09.400 Computer chose rock as well. 11:09.400 --> 11:11.050 And I get it's a draw. 11:11.050 --> 11:12.490 So that's pretty good. 11:13.780 --> 11:20.530 Now if I choose zero and the computer chose two, then this is going to be the statement that gets triggered 11:20.530 --> 11:21.820 and I win. 11:21.820 --> 11:23.350 So that's pretty good. 11:23.680 --> 11:30.310 Now what if I chose two for scissors and the computer chose zero. 11:30.640 --> 11:34.120 Well in this case rock beats scissors. 11:34.120 --> 11:37.000 So it should actually say I lose. 11:37.000 --> 11:40.360 But instead it says you typed an invalid number. 11:40.360 --> 11:43.150 So it defaulted to the else statement. 11:43.150 --> 11:49.360 Again, because this particular situation is not caused by any of these statements. 11:49.870 --> 11:51.760 So what do we have to do instead? 11:51.790 --> 12:01.480 Well, we actually need another Elif to say, well, if the computer choice was equal to zero and the 12:01.480 --> 12:03.790 user choice was equal to two. 12:03.820 --> 12:11.770 Well, this means that rock beats scissors, so I lose and the computer wins. 12:11.950 --> 12:16.300 Now, the final one that we need to catch is this case. 12:16.330 --> 12:25.660 If I type one for paper and computer chooses zero for rock, it again defaults to the else statement. 12:25.780 --> 12:30.130 Whereas in fact in this case it should tell me that I won. 12:30.160 --> 12:31.870 So what's missing here? 12:31.900 --> 12:35.980 Well, it's the partner to this particular statement. 12:36.100 --> 12:40.450 If computer choice is greater than user choice, then I lose. 12:40.450 --> 12:46.630 But on the other hand, if the user choice was greater than the computer choice. 12:46.660 --> 12:49.360 Then I actually should win. 12:51.340 --> 12:57.430 So now the final thing we might have to fix is this else statement. 12:57.460 --> 13:03.160 Now actually never gets called because this is what happens. 13:03.160 --> 13:06.610 So let's say that I choose 456. 13:06.640 --> 13:09.820 It tells me that computer chose to I win. 13:09.850 --> 13:10.870 What's happening here? 13:10.900 --> 13:15.910 Well, it's actually this particular line that's being carried out. 13:15.910 --> 13:18.490 User choice is greater than computer choice. 13:18.520 --> 13:19.990 This is not what we want. 13:20.020 --> 13:22.000 We want it to default to. 13:22.030 --> 13:23.590 You typed in invalid number. 13:23.590 --> 13:24.610 You lose. 13:24.610 --> 13:28.840 So we can't actually just use else in this situation. 13:28.870 --> 13:31.870 We actually need to provide a condition. 13:31.900 --> 13:40.930 So we're going to use Elif to check if the user choice is greater or equal to three. 13:41.200 --> 13:45.800 Now, the computer will never choose anything other than zero, one, and two. 13:45.830 --> 13:52.250 So we don't have to check that one, but the user could choose something above three or below zero, 13:52.250 --> 14:00.740 so we can use an Or statement to catch this, or if the user choice is less than zero. 14:00.830 --> 14:03.980 Well, in this case you typed an invalid number. 14:03.980 --> 14:05.210 You lose. 14:05.480 --> 14:08.210 But that's not all that we have to do. 14:08.210 --> 14:16.430 If we hit run and we again type some extraordinarily large number, you'll see that it still says computer 14:16.430 --> 14:17.210 chose one. 14:17.210 --> 14:18.200 You win. 14:18.230 --> 14:19.190 What's going on. 14:19.190 --> 14:22.610 We have this statement that should catch this situation. 14:22.610 --> 14:25.310 But it's right at the bottom. 14:25.310 --> 14:30.560 So it's not going to be checked until one of the previous ones are checked. 14:30.560 --> 14:34.910 Namely it's one of these that's going to be the problem. 14:34.910 --> 14:43.250 So what we have to do is we have to move this statement above all the lines so that we first check if 14:43.250 --> 14:48.590 the user choice is greater than three or less than zero. 14:48.770 --> 14:55.040 And if that's not true, do we actually continue checking to see who won the game? 14:55.370 --> 14:58.460 Now finally we can run our code. 14:58.490 --> 15:02.000 Type in invalid number and get you typed in invalid number. 15:02.030 --> 15:02.960 You lose. 15:03.770 --> 15:10.850 So now that we've actually got our logic all sorted out, the next step is to include our images. 15:10.880 --> 15:14.810 And to do that, we have to somehow match it up with these numbers. 15:14.810 --> 15:17.210 We have right zero, one and two. 15:17.240 --> 15:22.970 Now there's many, many ways that you could do this and you could solve this project. 15:22.970 --> 15:31.460 But the easiest way is probably putting the game images into a list where we have rock as the first 15:31.460 --> 15:36.350 one, paper as the second one, and scissors as the last one. 15:36.350 --> 15:43.350 So we're using the fact that lists have a Order that is always going to be followed. 15:43.350 --> 15:47.370 So we can now get hold of the rock picture by getting game images. 15:47.400 --> 15:48.120 Zero. 15:48.150 --> 15:55.500 We can get scissors by doing game images two and so on and so forth, and we can match those up to our 15:55.500 --> 15:58.470 choices, the user choice and the computer choice. 15:58.470 --> 16:06.000 So when the user chooses a number, then we're going to print from the game images. 16:06.000 --> 16:12.510 And we're going to use our little square brackets to select the image we want from this list. 16:12.510 --> 16:16.710 And the one that we want is going to be based on the user's choice. 16:16.740 --> 16:17.190 Right? 16:17.220 --> 16:19.680 Zero for rock, one for paper, two for scissors. 16:19.680 --> 16:26.640 So we're going to put user choice as the index to pick out an image from game images. 16:27.120 --> 16:31.320 The index can only be zero, 1 or 2. 16:31.350 --> 16:38.910 So we should only print the image if our user picked a number that's greater or equal to zero and less 16:38.910 --> 16:41.220 than or equal to two. 16:41.370 --> 16:48.000 Otherwise, our program will crash before we reach our checking code down here, where we tell our user 16:48.000 --> 16:50.910 that they've typed in an invalid number. 16:51.780 --> 16:58.920 Now, down here for the computer choice, instead of printing the number that the computer chose, I'm 16:58.920 --> 17:02.640 going to delete that and add a little colon. 17:03.480 --> 17:07.590 So that way it's going to show computer chose. 17:07.590 --> 17:13.140 And then I'm going to print the image of the choice that the computer made. 17:13.170 --> 17:15.300 So I'm going to add another print statement. 17:15.300 --> 17:17.370 I'm going to tap into the game images. 17:17.370 --> 17:23.790 And then inside some square brackets I'm going to use the computer choice which is going to be between 17:23.790 --> 17:30.240 zero, one and two as the index to pick out the corresponding image from my list. 17:30.270 --> 17:31.500 Game images. 17:31.530 --> 17:38.310 So now we're finally ready to run our code, and I'm going to choose zero for rock and the computer 17:38.310 --> 17:39.910 to chose paper. 17:39.910 --> 17:43.090 So paper beats rock, I lose. 17:43.450 --> 17:44.680 Let's try this again. 17:44.680 --> 17:45.040 I'm going. 17:45.070 --> 17:48.670 To choose scissors and computer chose scissors. 17:48.670 --> 17:49.750 It's a draw. 17:49.780 --> 17:58.300 Now we have completed the project by using everything from lists to randomization to variables to if 17:58.300 --> 18:00.970 statements and a whole lot of logic. 18:00.970 --> 18:05.170 So how did you get on with this project if you struggled? 18:05.170 --> 18:10.600 This is the time again to go back to it and maybe map things out using a flow diagram. 18:10.600 --> 18:15.790 But the important thing is that you got to write your own code and you've got to make it work, and 18:15.790 --> 18:20.920 this is the only way that you'll understand what's going on so that you can continue on. 18:20.920 --> 18:26.860 And as things get harder, you'll be able to learn more because you've already understood all of the 18:26.860 --> 18:28.180 previous knowledge. 18:28.210 --> 18:34.720 So I hope you had fun with me today, learning and building, and hopefully I will see you tomorrow 18:34.750 --> 18:35.890 bright and early. 18:35.890 --> 18:38.500 So that's goodnight from me for today.