1 00:00:01,359 --> 00:00:02,260 Hey, welcome back. 2 00:00:02,290 --> 00:00:10,990 In the previous video, you learned that you could create a class which would inherit the methods of 3 00:00:10,990 --> 00:00:12,280 another class. 4 00:00:13,330 --> 00:00:20,060 For example, our secure credit card class was able to inherit the validate method class. 5 00:00:20,080 --> 00:00:29,530 In other words, when we create an instance using secure credit cards, that instance has access to 6 00:00:29,530 --> 00:00:35,050 the validate methods which was defined in the credit card class. 7 00:00:36,120 --> 00:00:39,720 So this method was called in here. 8 00:00:40,290 --> 00:00:46,850 Now, sometimes that method that you are inheriting might not be enough. 9 00:00:46,860 --> 00:00:49,950 You might want to change something from that method. 10 00:00:50,310 --> 00:00:56,220 In that case, what you want to do in the child class is you want to override that method. 11 00:00:56,250 --> 00:00:57,990 So let's take an example. 12 00:00:57,990 --> 00:00:59,280 In the Python console. 13 00:00:59,280 --> 00:01:01,500 I will not be modifying the code for this. 14 00:01:01,500 --> 00:01:07,500 I just want to show you the concept in this video, the concept behind overwriting a method. 15 00:01:08,130 --> 00:01:11,490 So let's take a ticket class, right? 16 00:01:12,330 --> 00:01:15,090 It has an init method. 17 00:01:16,180 --> 00:01:18,910 Let's just pass here to keep it simple. 18 00:01:18,910 --> 00:01:22,570 And then this ticket method has this generate method, right? 19 00:01:23,080 --> 00:01:25,030 Which returns. 20 00:01:26,300 --> 00:01:31,100 Something like, Hello, this is your ticket. 21 00:01:31,100 --> 00:01:34,850 So I'm not including any parameters here. 22 00:01:35,300 --> 00:01:39,140 I just want to make a point about inheritance. 23 00:01:39,140 --> 00:01:41,900 So that is the ticket class right now. 24 00:01:42,110 --> 00:01:47,450 If you want to create a class which inherits from that class, let's say digital. 25 00:01:48,990 --> 00:01:49,800 Ticket. 26 00:01:50,670 --> 00:01:53,520 So we would supply tickets here. 27 00:01:54,840 --> 00:02:01,530 And then perhaps you want to add more methods such as define download. 28 00:02:01,830 --> 00:02:03,630 They can download the tickets. 29 00:02:03,660 --> 00:02:06,060 You have some codes here and so on. 30 00:02:06,180 --> 00:02:15,720 And then perhaps you might want to override that method because you might want to return something else 31 00:02:15,720 --> 00:02:17,340 instead of that strings. 32 00:02:17,340 --> 00:02:18,060 Right. 33 00:02:18,090 --> 00:02:23,660 In that case, all you have to do is define the method again. 34 00:02:23,670 --> 00:02:28,440 So the method name should be exactly the same as in the parent class. 35 00:02:28,920 --> 00:02:30,030 Generate. 36 00:02:31,110 --> 00:02:36,670 And then returns something else like, Hi, this is your ticket. 37 00:02:36,690 --> 00:02:39,740 So now this string is different from that, right? 38 00:02:39,750 --> 00:02:41,490 So let's execute this class. 39 00:02:41,940 --> 00:02:46,470 Let's instantiate digital ticket. 40 00:02:46,590 --> 00:02:49,560 It doesn't take any arguments, right? 41 00:02:49,560 --> 00:02:55,250 Because the init method doesn't take any other parameters other than self. 42 00:02:55,260 --> 00:02:56,760 So that is the method. 43 00:02:56,790 --> 00:03:00,900 Now generate will of course. 44 00:03:03,420 --> 00:03:04,310 Output. 45 00:03:04,320 --> 00:03:04,920 Hi. 46 00:03:04,920 --> 00:03:06,180 This is your ticket. 47 00:03:07,170 --> 00:03:10,560 So it outputs this string instead of that. 48 00:03:11,070 --> 00:03:19,770 So you can override a method of the parent class by defining that method in the child's class. 49 00:03:20,310 --> 00:03:30,150 Of course, if we say TW is equal to tickets, which is the parent class to generate, of course it 50 00:03:30,150 --> 00:03:30,870 returns. 51 00:03:30,870 --> 00:03:32,670 Hello, this is your ticket. 52 00:03:32,820 --> 00:03:40,650 So that is a string of the ticket class because when you inherit from a class, you do not modify the 53 00:03:40,650 --> 00:03:44,520 parent class, you only modify the child class. 54 00:03:44,820 --> 00:03:48,080 And that's the concept I wanted to talk about in this video. 55 00:03:48,090 --> 00:03:50,160 So thanks a lot and see you in the next one.