WEBVTT 00:00.920 --> 00:07.580 Most lists you create will be dynamic, meaning you will build a list and then add and remove elements 00:07.580 --> 00:09.980 from it as your program runs its course. 00:10.100 --> 00:15.590 For example, you might create a game in which your player has to shoot aliens out of the sky. 00:15.860 --> 00:21.800 You could store the initial set of aliens in a list and or remove an alien from the list each time one 00:21.800 --> 00:23.120 is shot down. 00:23.120 --> 00:27.680 So each time a new alien appears on the screen, you add it to the list. 00:27.710 --> 00:35.150 Your list of aliens will increase and decrease in length throughout the course of the game. 00:35.150 --> 00:42.290 So now the syntax of for modifying an element is similar to the syntax for accessing an element. 00:42.290 --> 00:49.700 Unless you change an element, you use the name of the list followed by the index index of the element 00:49.700 --> 00:56.690 you want to change and then provide the new value and you want to item to have. 00:56.720 --> 01:00.960 For example, say we have a list of course, topics. 01:01.870 --> 01:02.050 On. 01:02.050 --> 01:04.600 The first item in the list is car. 01:05.610 --> 01:08.130 The car is not actually called subject name, right? 01:08.130 --> 01:15.780 So we can change the value of this first item after the list has been created. 01:15.990 --> 01:19.230 So now we will use the. 01:20.850 --> 01:22.320 Course topics. 01:22.590 --> 01:23.280 Right. 01:25.220 --> 01:27.680 Power is the zeroth element. 01:28.340 --> 01:33.470 Index is zero and we will make this car repair. 01:33.500 --> 01:36.470 The car repair is actually like a course topic, right? 01:36.620 --> 01:37.410 That's it. 01:37.430 --> 01:41.930 So now we will print the. 01:42.740 --> 01:43.430 Course. 01:43.430 --> 01:45.650 Or let's actually print the. 01:46.400 --> 01:48.880 Course Topics and index zero. 01:48.880 --> 01:50.140 Let's print the car repair. 01:50.140 --> 01:50.740 Right. 01:51.370 --> 01:53.230 Let's know how it affected here. 01:53.230 --> 01:56.890 As you can see here, car repair has changed. 01:56.890 --> 02:01.330 Here we define the the course topics with. 02:02.160 --> 02:02.420 Car. 02:02.580 --> 02:03.910 Car as the first element. 02:03.920 --> 02:08.340 And we change the value of the first item to car repair. 02:08.360 --> 02:15.380 The output shows the first item has been changed while the rest of the list stays the same. 02:15.710 --> 02:19.160 So you can change the value of any item in a list, not just the first item. 02:19.160 --> 02:20.560 For example, let's. 02:21.290 --> 02:24.030 2012. 02:24.050 --> 02:27.800 So instead of it changing to car repair, we will make it. 02:28.460 --> 02:31.250 Let's actually make it the. 02:33.490 --> 02:34.510 Kotlin, right? 02:34.540 --> 02:35.370 Kotlin. 02:35.380 --> 02:36.730 Let's try it now. 02:36.730 --> 02:42.100 And as you can see here, oops, We need to also change the print function because we are now seeing 02:42.100 --> 02:44.740 the elements zero, not two. 02:44.920 --> 02:48.160 And as you can see here, we have a Kotlin. 02:49.520 --> 02:54.110 So also you want want to add a new element to a list for many reasons, right? 02:54.110 --> 03:01.120 So, for example, you might want to make a new aliens this funny aliens to appear in a game. 03:01.130 --> 03:08.180 Now you add a new data to a visualization or add a new registered users to make a website your build. 03:08.180 --> 03:14.540 So Python provides several ways to add new data to existing lists. 03:15.740 --> 03:20.240 So now let's let's start with the appending element. 03:20.250 --> 03:21.700 So the end of the list, right? 03:21.710 --> 03:26.120 So now we can also delete this alias here. 03:26.930 --> 03:28.370 So here. 03:29.390 --> 03:34.970 The simplest way to add a new element to a list here. 03:37.190 --> 03:41.330 So the simplest way to add a new element to a list. 03:42.080 --> 03:45.330 Is to append the item to the list. 03:45.350 --> 03:51.650 So when you append an item to the list, the new element is added to the end of the list using the same 03:51.650 --> 03:53.240 list we had in the previous example. 03:53.240 --> 03:54.680 We will add a new element. 03:55.160 --> 03:56.240 New element. 03:56.420 --> 03:58.760 Let's make Kotlin or Swift Write. 03:59.500 --> 04:03.460 So now we will write course topics. 04:03.490 --> 04:08.080 Course Topics dot append. 04:08.320 --> 04:10.840 Here we will enter the Kotlin. 04:10.840 --> 04:13.930 Also we will make the course topics. 04:13.960 --> 04:18.310 Course Topics that append Swift. 04:19.460 --> 04:20.060 Swift. 04:20.810 --> 04:25.460 And we will also have course topics that append. 04:26.660 --> 04:28.100 C sharp or. 04:29.630 --> 04:30.440 C-sharp here. 04:30.800 --> 04:34.970 Now, what we're going to do is now there's a here. 04:35.090 --> 04:38.760 So let's write that down what we have as a list. 04:38.780 --> 04:44.390 So here we have item 012. 04:45.250 --> 04:46.810 Pray for. 04:51.370 --> 04:53.470 One, two, three, four, five. 04:55.940 --> 04:57.400 Of let's make it. 04:57.410 --> 04:58.970 Let's actually make it from here. 04:59.920 --> 05:04.240 Zero one, two, three, four. 05:05.590 --> 05:06.280 Five. 05:07.840 --> 05:08.320 Thanks. 05:10.650 --> 05:11.580 One, two. 05:13.270 --> 05:15.480 Three, four, five, six, seven. 05:15.490 --> 05:16.000 Here. 05:16.180 --> 05:17.770 And seven. 05:18.380 --> 05:21.860 So here we will make this like that. 05:27.810 --> 05:28.260 Here. 05:40.660 --> 05:41.230 So. 05:42.240 --> 05:43.440 In first list. 05:44.790 --> 05:47.160 Remember, we had the. 05:47.950 --> 05:49.330 Actually here. 05:49.330 --> 05:52.450 So in verses we have car right? 05:52.600 --> 05:53.410 Car. 05:56.400 --> 05:56.910 Are. 05:58.260 --> 06:00.060 The first is Kotlin. 06:01.060 --> 06:02.500 I will make it short. 06:02.830 --> 06:05.350 Kotlin or Android. 06:05.350 --> 06:07.540 Here A and. 06:10.170 --> 06:12.600 Here and Java here. 06:14.570 --> 06:16.070 Var python. 06:21.330 --> 06:26.170 And digital forensics DVR. 06:26.280 --> 06:27.660 I will make it short here. 06:29.820 --> 06:30.100 Was. 06:37.570 --> 06:38.050 He. 06:40.630 --> 06:41.020 He. 06:43.130 --> 06:44.660 Are digital forensics. 06:45.140 --> 06:50.600 And here remember we added here items, right? 06:54.300 --> 06:57.150 So these items were Kotlin. 06:57.270 --> 07:00.750 So remember, Kotlin added first year. 07:00.750 --> 07:02.910 So after this we are adding Kotlin. 07:02.910 --> 07:05.640 So the Kotlin will be added first. 07:05.640 --> 07:07.950 In this case, it's going to be Remember what? 07:09.350 --> 07:10.030 Remember? 07:10.040 --> 07:10.640 Remember? 07:10.640 --> 07:11.120 Yeah. 07:11.150 --> 07:14.210 Kotlin is going to be fifth item on the list index. 07:16.250 --> 07:16.700 But. 07:17.560 --> 07:17.950 Lynn. 07:19.010 --> 07:19.460 Or no? 07:19.460 --> 07:19.880 Yes. 07:19.880 --> 07:21.170 Kotlin here. 07:21.170 --> 07:23.690 And we also have the swift here. 07:24.080 --> 07:27.140 It's gonna it's added secondly. 07:28.440 --> 07:30.960 So are we going to make it six item? 07:33.820 --> 07:34.090 We're. 07:35.010 --> 07:42.030 Because as you remember here, this function appends at the end of the list. 07:42.270 --> 07:47.580 So if you Kotlin ends here, here, Kotlin is here. 07:47.760 --> 07:49.440 After that, we are adding sweat. 07:49.440 --> 07:59.340 So Cutlan Swift is after Kotlin and we add the C sharp because C sharp is after the swift. 07:59.580 --> 08:00.150 So. 08:00.150 --> 08:02.910 And we also have C sharp here. 08:04.540 --> 08:05.410 That's it. 08:05.440 --> 08:09.930 Here we add the append method. 08:09.940 --> 08:17.250 Add three items to the end of the list without affecting any other elements in the list. 08:17.260 --> 08:20.890 So the append method makes it easy to build the list dynamically. 08:20.890 --> 08:26.950 For example, you can start with an empty list and then add items to the list using series of append 08:26.950 --> 08:28.620 calls using an empty list. 08:28.630 --> 08:35.230 Let's add the elements to our core, to our list here. 08:35.230 --> 08:38.140 So now let me look at the first lecture. 08:38.140 --> 08:39.490 Yeah, that's okay. 08:39.550 --> 08:46.330 So now we will instead of this, we will add and also use this here. 08:46.780 --> 08:49.210 So now we will create a new list. 08:51.390 --> 08:58.050 Actually, let's actually, instead of let's print the list course topics to show you what changed. 08:58.080 --> 08:58.950 Seven. 09:00.310 --> 09:02.190 And as you can see, it's C-sharp. 09:02.380 --> 09:05.470 Six is swift. 09:08.960 --> 09:11.480 The fifth is Kotlin. 09:11.510 --> 09:12.500 The fourth is. 09:12.530 --> 09:14.750 And as you can see, these are not changed. 09:14.780 --> 09:16.100 Affected by the change. 09:16.880 --> 09:18.110 These are not here. 09:18.110 --> 09:20.240 And as you can see, one. 09:20.330 --> 09:21.560 Lastly, zero. 09:25.110 --> 09:26.010 Now. 09:26.950 --> 09:31.330 I will take this note here and I will share this file with you. 09:33.190 --> 09:39.120 Now here we will delete these quotes here and instead we will add course. 09:39.920 --> 09:42.370 Or let's actually course names, right? 09:42.580 --> 09:45.910 Course names or courses here. 09:45.950 --> 09:48.130 Oxley Courses. 09:48.800 --> 09:52.480 And here we will make the list. 09:52.490 --> 09:52.940 Right. 09:52.940 --> 09:53.780 So. 09:54.660 --> 09:59.880 If you do write this code, this will create the. 10:00.960 --> 10:01.890 This will. 10:06.720 --> 10:07.590 I'm sorry. 10:08.480 --> 10:11.780 So this will create. 10:13.260 --> 10:14.370 Empty list. 10:21.490 --> 10:26.800 This will create an empty list here and you can add or delete later. 10:27.610 --> 10:35.110 So now, since we created this, the append method makes it easy to build list dynamically. 10:35.290 --> 10:38.380 So now we will use auxiliary courses. 10:38.380 --> 10:41.740 So the courses that append, we will add new course. 10:41.740 --> 10:42.310 Right? 10:42.670 --> 10:47.500 Android Kotlin training in 33 hours. 10:50.590 --> 11:00.850 And here after that we will Oxley courses that append Python training best Python course in the world. 11:00.850 --> 11:01.450 Right? 11:01.720 --> 11:04.120 In the world. 11:06.320 --> 11:08.330 The excellent courses that are pending. 11:09.170 --> 11:14.900 Ethical hacking with Python in 20 hours. 11:17.070 --> 11:17.560 Oxley. 11:18.720 --> 11:21.870 Oxley courses that append and we will make. 11:22.020 --> 11:24.270 It's actually right. 11:26.820 --> 11:27.900 Designing. 11:29.490 --> 11:35.040 Database models with my SQL. 11:35.770 --> 11:36.600 That's it. 11:36.610 --> 11:40.390 Now we will write print this down. 11:42.090 --> 11:42.630 Here. 11:43.020 --> 11:44.130 Let's print. 11:45.350 --> 11:47.960 Oxer the courses and one. 11:48.870 --> 11:51.410 Best courses in the world, best Python courses in the world. 11:51.420 --> 11:52.830 This is the first year. 11:53.010 --> 11:56.550 So actually this number is zero one. 11:57.410 --> 11:57.840 Two. 11:58.280 --> 11:58.790 Three. 12:03.630 --> 12:09.300 Now we will write zero under coding training in 33 hours. 12:09.510 --> 12:12.330 One Python course in the world. 12:12.750 --> 12:22.860 Two Ethical hacking with Python and 20 hours three designing database models with MySQL. 12:22.890 --> 12:30.990 So building list this way is very common because you often want to know the data your users want to 12:30.990 --> 12:33.630 store in a program until after the program is running, right? 12:33.630 --> 12:42.510 So to put your users in control, start by defining an empty list that still hold the user's value. 12:42.510 --> 12:46.800 Then append each new value provided to the list you just created here.