WEBVTT 00:01.140 --> 00:04.080 Many reasons exist to store a set of numbers. 00:04.080 --> 00:08.940 For example, you will need to keep track of the positions of each character in a game, and you might 00:08.940 --> 00:11.800 want to keep track of a player's high scores as well. 00:11.820 --> 00:19.110 In data visualizations you will almost always work with a sets of numbers such as temperatures, distances, 00:19.110 --> 00:25.040 population size or latitude, longitude, values, among other types of numerical sets. 00:25.050 --> 00:30.990 So lists are ideal for storing sets of numbers, and Python provides a variety of tools to help you 00:30.990 --> 00:34.470 work efficiently with lists of numbers. 00:34.470 --> 00:43.170 So once you understand how to use these tools effectively, your code will work well even when your 00:43.170 --> 00:45.510 list contains millions of items. 00:45.690 --> 00:48.090 So you can also use the range function. 00:48.090 --> 00:52.100 So Python's range function makes it easy to generate a series numbers. 00:52.110 --> 00:57.120 For example, you can use the range function to print a series of numbers like this. 00:57.120 --> 01:03.820 For my value, my value here in range, for example, from 1 to 10. 01:03.820 --> 01:09.280 And here we will print the print my value. 01:09.280 --> 01:12.430 And here you will see us here. 01:12.970 --> 01:19.630 And here you will see range from one, two, three, four, five, six, seven, eight, nine here. 01:19.630 --> 01:26.890 So although this code looks like it should print the numbers from 1 to 10, it doesn't print the number 01:26.890 --> 01:34.030 ten in this example range prints only the numbers from one through ten. 01:34.030 --> 01:39.610 So I want to explain this by drawing something on the screen here like that, for example, this is 01:39.610 --> 01:40.570 Range. 01:42.600 --> 01:43.380 Range. 01:45.240 --> 01:48.090 Here, for example, we wanted variables. 01:48.090 --> 01:57.340 One, two, three, four, five, six, seven, eight, nine, nine. 01:57.510 --> 01:57.770 Oops. 01:58.830 --> 02:00.840 Nine and ten. 02:00.990 --> 02:09.390 Here we when we ask range for a number from 1 to 10, it will give us from here. 02:10.130 --> 02:11.060 And. 02:11.760 --> 02:14.400 From 1 to 9. 02:14.400 --> 02:16.980 So this is the number. 02:17.720 --> 02:19.580 This code will give us here. 02:19.730 --> 02:20.690 So. 02:21.840 --> 02:30.420 As I said in this code, the range prints only numbers from one truth for truth nine. 02:30.780 --> 02:32.250 It's let's run it again. 02:32.250 --> 02:33.390 And here. 02:33.390 --> 02:38.460 So this is the another result of the off by one behavior you will see often in programming languages 02:38.490 --> 02:45.510 and the range function causes Python to start counting at the first value you give it and it stops when 02:45.510 --> 02:49.680 it reaches the second value you provide because it stops at the second value. 02:49.710 --> 02:58.380 The output never contains the end value, which would have been ten in this case to print numbers one 02:58.750 --> 03:01.770 from 1 to 10, you will do this. 03:02.220 --> 03:03.360 Just 11, right? 03:03.360 --> 03:04.950 11 And that's it. 03:04.950 --> 03:05.130 Here. 03:05.130 --> 03:07.770 As you can see, we printed values from 1 to 10. 03:07.770 --> 03:14.550 So if your output is different from what you expect when you are using range, try adjusting your end 03:14.550 --> 03:16.050 value by one. 03:16.050 --> 03:23.230 So you can also pass range only one argument and it will start a sequence of numbers at zero, for example 03:23.230 --> 03:24.220 range. 03:25.110 --> 03:26.010 Range. 03:27.860 --> 03:29.060 Six here. 03:30.930 --> 03:35.460 Will return the numbers from 0 to 6. 03:35.670 --> 03:39.060 So you can also use the range to make a list of numbers. 03:39.060 --> 03:45.090 So if you want to make a list of numbers, you can convert the results of range directly into list using 03:45.090 --> 03:46.320 the list function. 03:46.320 --> 03:54.690 So when you wrap list around the call to range function, the output will be a list of numbers in the 03:54.690 --> 03:56.790 example the previous section. 03:57.600 --> 04:04.950 In the example of previous section, we simply printed out series of numbers and we can use list to 04:04.950 --> 04:07.560 convert that same set of numbers into a list. 04:07.590 --> 04:13.710 So in order to do that, we will do numbers or my special numbers. 04:13.710 --> 04:15.060 My special. 04:16.540 --> 04:18.070 Actual numbers. 04:18.220 --> 04:24.010 Numbers equals list here and range one. 04:25.820 --> 04:29.600 One 6 or 111 here. 04:29.600 --> 04:30.890 So now. 04:32.610 --> 04:38.940 We have to add here and we will add after that, we will print the my special numbers. 04:38.940 --> 04:39.660 That's it. 04:39.690 --> 04:45.360 Here you can see the one, two, three, four, five, six, seven, eight, nine, ten. 04:45.690 --> 04:50.940 So we can also use the range function to tell Python the skip numbers in a given range. 04:50.940 --> 04:57.930 If you pass a third argument to a range here, Python uses that value as a step size when generating 04:57.930 --> 04:58.530 numbers. 04:58.530 --> 05:00.630 For example, here is our list. 05:00.630 --> 05:11.700 The even numbers between 1 and 10 we will do here too, and we will do two here again and here. 05:11.700 --> 05:15.480 And as you can see here, two, four, six, eight and ten. 05:15.480 --> 05:23.790 So in this example, the range function starts with the value two and then adds two to that value. 05:23.790 --> 05:28.380 It adds repeatedly until it reaches or passes the end value. 05:28.380 --> 05:32.310 11 I want to also illustrate this on screen here. 05:32.310 --> 05:38.010 So here we have one, two, three, four, five. 05:40.070 --> 05:43.820 Five, six, seven, eight. 05:44.990 --> 05:45.710 Nine. 05:47.650 --> 05:48.220 Seven. 05:49.010 --> 05:51.080 Eight, nine, ten. 05:51.110 --> 05:51.770 Here. 05:52.220 --> 05:53.630 So here. 05:54.920 --> 05:56.170 What you see is. 05:56.290 --> 06:04.090 So here we will we are seeing that we will start from two and end four from 1011. 06:04.090 --> 06:07.900 But this means ten here, as you as we explained here. 06:07.900 --> 06:10.570 So we will start from the two here. 06:10.570 --> 06:12.820 So we will start first from this. 06:14.190 --> 06:20.310 Two four, because as you can see here, we are passing two in each number. 06:20.310 --> 06:25.410 And then we here we come here and here we go to. 06:27.200 --> 06:27.740 Six. 06:27.740 --> 06:34.130 And here we come, here and here we go to eight, and here we are. 06:34.130 --> 06:37.550 And then we are going to ten. 06:37.550 --> 06:39.650 And this is where our. 06:41.100 --> 06:42.180 Range ends. 06:42.180 --> 06:47.630 So you can create almost any sets of numbers or you want to use the. 06:47.640 --> 06:55.470 So you can also create you can create almost any set of numbers you want to using the range function. 06:55.470 --> 07:00.630 So for example, consider how might make a list of the first ten square numbers. 07:00.630 --> 07:07.530 That is the square of each integers from one through ten in Python, which is two asterisks like that. 07:07.800 --> 07:09.690 So let's actually close this. 07:09.690 --> 07:16.650 So now here's how you might plot the first ten square numbers onto a list. 07:16.650 --> 07:26.070 So here we have my special or my squares here, squares, and here we will create an empty list. 07:26.100 --> 07:32.310 Now we will use the for loop my my value here in range. 07:32.310 --> 07:36.420 And here we will start from 1 to 11. 07:36.960 --> 07:46.890 And here we will use the my squares here equals my value asterisk to add an asterisk here. 07:47.160 --> 07:54.330 And two and here we will use my my ears here that append. 07:55.460 --> 07:56.110 Append. 08:00.080 --> 08:00.500 Yeah. 08:00.500 --> 08:01.760 My value here. 08:03.260 --> 08:03.800 You must. 08:07.970 --> 08:11.120 Here my squares that append. 08:25.790 --> 08:30.320 My square here and it will change with my square equals my value. 08:30.440 --> 08:36.920 62 And here we will use my squares that append the my. 08:38.790 --> 08:39.360 Square. 08:39.750 --> 08:40.710 And that's it. 08:42.300 --> 08:45.660 And after that, of course, we will need to print the squares here. 08:49.040 --> 08:50.510 Here, but outside the for loop. 08:50.510 --> 08:57.920 As you can see here, we are printing outside for loop workers or my spare. 08:59.180 --> 09:00.770 Yeah, that's it. 09:00.800 --> 09:02.600 Now let's run it. 09:03.820 --> 09:12.260 And as you can see here, one, four, nine, 16, 25, 38, 49, 64, 81 and 100. 09:12.280 --> 09:15.730 So we start with an empty list called squares. 09:15.850 --> 09:17.110 Actually, let me here. 09:17.140 --> 09:24.550 So here we start with the empty list called my squares. 09:24.820 --> 09:26.530 Here, let's actually use that marker. 09:26.560 --> 09:29.860 So here we start with the empty list called my squares. 09:29.890 --> 09:35.800 Then we tell Python to loop through each value. 09:36.400 --> 09:38.470 Loop through each value. 09:39.400 --> 09:40.540 From one. 09:41.790 --> 09:43.500 210. 09:43.800 --> 09:48.930 In this case, we read write 11 using the range function. 09:48.930 --> 09:57.300 So inside the loop, the current value is raised to the second power and assigned to the variable. 09:57.720 --> 09:59.220 My square. 09:59.220 --> 09:59.880 Here. 10:00.090 --> 10:06.480 Each new value of square is then appended to my square list here. 10:06.570 --> 10:09.150 As you can see here we are using append here. 10:09.150 --> 10:10.260 So this worked like that. 10:10.260 --> 10:16.740 For example, this is our my squares here and here we added and then another loop comes. 10:16.740 --> 10:20.310 We added another value and then another look loop comes. 10:20.310 --> 10:25.230 We added another value inside it and until the ten times here. 10:25.950 --> 10:27.840 So that's it. 10:28.110 --> 10:36.840 And finally, when the loop has finished running, the list of squares is printed on the screen.