WEBVTT 00:00.170 --> 00:07.460 This is the second activity of this course, and in this activity we are going to ask the user to type 00:07.460 --> 00:08.150 something. 00:08.150 --> 00:09.290 We're going to get this. 00:09.290 --> 00:14.510 So we're going to get the input and we are going to validate the user input okay. 00:14.510 --> 00:18.080 So this is something that's done very often in programming. 00:18.110 --> 00:23.210 And before I give you the challenge I actually need to show you one more function that you didn't know. 00:23.210 --> 00:25.880 It's actually how to get the user input. 00:25.880 --> 00:33.560 So you have seen that you can print something for example with the print function like that okay. 00:33.590 --> 00:36.800 So in this case it's basically an output. 00:36.800 --> 00:41.180 So from the program to the user here the user is going to be the shell okay. 00:41.210 --> 00:43.820 It's whatever you type or that you see on the shell. 00:43.820 --> 00:46.280 So with print you have an output. 00:46.310 --> 00:54.260 Now to get the user to actually type something here and get it into your program, you can use the input 00:54.980 --> 00:56.090 function okay. 00:56.120 --> 00:58.160 So you have print and you have input. 00:58.160 --> 01:05.100 If I run this you will see the program problem is kind of hanging there, and I can just type some text 01:05.130 --> 01:12.240 or some numbers or whatever, and I press enter and you can see now the input function returns inside 01:12.240 --> 01:13.440 the parentheses. 01:13.440 --> 01:15.210 Here I can type a prompt. 01:15.240 --> 01:15.420 Okay. 01:15.450 --> 01:17.040 So that would be a bit better. 01:17.040 --> 01:23.580 So for example enter a number with a colon a space just like that. 01:23.580 --> 01:26.940 So if I run again you see now we have entered a number. 01:26.940 --> 01:28.380 So it's a bit more explicit. 01:28.380 --> 01:32.850 So now I can say for example 56 I press enter. 01:32.970 --> 01:33.480 All right. 01:33.510 --> 01:36.120 Now the thing is we don't do anything with this input. 01:36.120 --> 01:38.400 So I'm going to save this inside. 01:38.400 --> 01:46.710 So because I asked for a number I'm going to save it inside a variable named number is equal to input 01:46.740 --> 01:47.430 okay. 01:47.880 --> 01:52.920 This is first going to ask enter a number to get the input from the shell. 01:52.920 --> 01:56.550 And to store this value inside the number variable. 01:56.550 --> 01:58.140 Still it's not going to print anything. 01:58.140 --> 02:01.360 So then I can print a Uh, number. 02:01.360 --> 02:05.980 So I'm just going to print back what I typed on the terminal. 02:06.610 --> 02:07.750 Let's run this. 02:07.750 --> 02:10.120 Enter a number one, two, three. 02:10.120 --> 02:11.890 So 123. 02:11.920 --> 02:13.180 Let's press enter. 02:13.180 --> 02:15.910 And you can see 123. 02:15.910 --> 02:18.610 So we just print it back the number. 02:18.610 --> 02:21.310 But now there is one thing that you need to know. 02:21.310 --> 02:23.980 And that will be very important for you to complete the challenge. 02:23.980 --> 02:29.290 Is that what you get here, even if you ask for a number, what you get here is not a number. 02:29.290 --> 02:35.020 What you get here with the input function is a string, and that will be saved as a string. 02:35.020 --> 02:36.700 Even if you write number as a variable. 02:36.730 --> 02:40.480 Okay, the name of the variable doesn't really mean anything for the program. 02:40.570 --> 02:41.740 It's still going to be a string. 02:41.740 --> 02:49.420 How to verify that I'm going to write type here type number I'm going to print the type of the data 02:49.450 --> 02:50.710 I get okay. 02:50.740 --> 02:52.150 So for example I put one. 02:52.180 --> 02:54.310 You can see we have a string. 02:54.310 --> 02:59.110 So what we receive here inside the variable number is not one. 02:59.290 --> 03:01.860 It is the string one. 03:02.340 --> 03:02.610 Okay. 03:02.640 --> 03:10.080 So that's going to be a problem if you want to use this variable as an integer number later on. 03:10.110 --> 03:16.560 And so what we can do is we can cast a value to another type okay. 03:16.590 --> 03:24.030 So for example here to make sure that we have an integer going to number we can use the int function. 03:24.030 --> 03:26.910 And I'm going to open parentheses and close parentheses. 03:26.910 --> 03:33.420 Here you can see with the int keyword here that's with syntax highlighting I can cast whatever is in 03:33.420 --> 03:35.280 the parentheses to an integer. 03:35.280 --> 03:38.280 So what's going to happen here is we first have the input. 03:38.280 --> 03:42.090 So we're going to get the data from the shell. 03:42.090 --> 03:44.640 And we're going to cast this into an integer. 03:44.820 --> 03:50.610 Now if I run this and I put the number you can see now we have an integer number okay. 03:50.640 --> 03:52.350 So that would be helpful for our program. 03:52.350 --> 03:56.190 You can also you can cast to int but you can also cast to float. 03:56.190 --> 03:57.660 For example like this. 03:57.660 --> 04:00.930 You can cast to a string with str okay. 04:00.960 --> 04:04.090 So you can cast two different data types here. 04:04.090 --> 04:05.170 We're going to use int. 04:05.200 --> 04:05.560 Okay. 04:05.590 --> 04:08.200 And now I can explain what is going to be the challenge. 04:08.200 --> 04:09.910 So I'm going to remove this print here. 04:10.570 --> 04:12.490 And actually I'm going to change the prompt. 04:12.490 --> 04:18.400 Enter a number between 1 and 100. 04:18.400 --> 04:23.890 So we are asking the user to enter a number that should be between 1 and 100. 04:23.920 --> 04:27.490 Of course the user can type whatever they want here. 04:27.520 --> 04:34.720 And what we want to do in our program is to validate that the number is actually between 1 and 100. 04:34.720 --> 04:36.940 So you already have the first line of the program. 04:36.940 --> 04:43.840 And then you are going to need to create a condition with an if block, maybe with if and else to say 04:43.840 --> 04:46.840 that the number is wrong or the number is correct. 04:46.870 --> 04:47.380 All right. 04:47.380 --> 04:49.810 And I will see you in the next video for the solution. 04:49.810 --> 04:53.980 Make sure you take enough time to think about it to try some things. 04:54.010 --> 04:58.600 Okay, maybe go back to the previous lessons, but make sure that you practice on your own. 04:58.600 --> 05:01.750 That's really important for you to make progress.