1 00:00:05,310 --> 00:00:09,330 Welcome back, everyone, to this series of lectures where we're going to be discussing the details 2 00:00:09,600 --> 00:00:14,790 of object oriented programming and part one, we're just going to have a slide based overview of the 3 00:00:14,790 --> 00:00:15,750 syntax structure. 4 00:00:17,280 --> 00:00:23,040 So Opie, or object oriented programming allows programmers to create their own objects to have methods 5 00:00:23,040 --> 00:00:23,850 and attributes. 6 00:00:24,270 --> 00:00:30,540 Recall that after we defined a string or list or dictionary or other data type objects in Python, you 7 00:00:30,540 --> 00:00:34,560 were actually able to call methods offer them with the DOP method name syntax. 8 00:00:35,700 --> 00:00:41,850 And these methods act as functions that use information about the object to return results or change 9 00:00:41,850 --> 00:00:42,780 the current object. 10 00:00:43,050 --> 00:00:49,200 For example, this includes a pending an item to a list or counting the occurrences of an element and 11 00:00:49,200 --> 00:00:49,650 a tuple. 12 00:00:51,090 --> 00:00:54,410 OPI allows users to create than their own objects. 13 00:00:54,800 --> 00:00:58,280 The syntax format, however, is often confusing when it's first encountered. 14 00:00:58,670 --> 00:01:02,300 And also, if you're a beginner in Python, you've only used functions so far. 15 00:01:02,600 --> 00:01:08,690 Sometimes it's a little confusing of why it's actually useful to define things as a class in an object. 16 00:01:09,110 --> 00:01:15,190 But in general, object oriented programming allows us to create code that is repeatable and organized. 17 00:01:15,230 --> 00:01:20,210 And more importantly, it's a feature that Django uses quite often, so we do need to understand it. 18 00:01:21,940 --> 00:01:27,280 For much larger scripts of Python code, functions by themselves usually are enough for organization 19 00:01:27,280 --> 00:01:33,550 and repeatability, and commonly repeated tasks and objects can be the of up to create code that is 20 00:01:33,550 --> 00:01:35,020 more usable and readable. 21 00:01:35,200 --> 00:01:38,080 So let's check out the general syntax with a simple example. 22 00:01:39,480 --> 00:01:45,900 So here I have a very simple example of a object oriented programming approach to creating your own 23 00:01:45,900 --> 00:01:47,520 object using class. 24 00:01:47,820 --> 00:01:51,270 So let's go through the main parts of this actual code. 25 00:01:52,530 --> 00:01:58,560 So at the top, in a similar fashion to the way you use the ADF keyword to define a function, you use 26 00:01:58,560 --> 00:02:03,120 the class keyword to define a class or object in Python. 27 00:02:03,480 --> 00:02:08,639 And notice by convention classes use camel case instead of a snake case. 28 00:02:08,820 --> 00:02:13,140 That way, when you're actually calling them in your code, you can tell whether using a function or 29 00:02:13,140 --> 00:02:13,710 a class. 30 00:02:14,880 --> 00:02:21,480 Then there is the in it call, which is the instantiation or initialization call for the actual class. 31 00:02:21,960 --> 00:02:28,380 This is going to help define what parameters or arguments you need to actually pass into the class when 32 00:02:28,380 --> 00:02:32,670 you create a new instance of the class and notice the actual syntax here. 33 00:02:33,450 --> 00:02:38,130 You're going to end up actually passing in parameters and then you're going to use what's known as the 34 00:02:38,130 --> 00:02:42,870 self keyword to assign them to that particular instance of the class. 35 00:02:43,770 --> 00:02:50,100 So here what we're saying is we're passing in some value for parameter two, and then I'm assigning 36 00:02:50,310 --> 00:02:57,540 that parameter to the actual class by saying self-report parameter to essentially linking it to that 37 00:02:57,540 --> 00:02:59,550 particular instance of the class. 38 00:02:59,880 --> 00:03:06,360 So Param two is what the user passes in and self that Param two is, then how we define it and link 39 00:03:06,360 --> 00:03:08,640 it to an instance of the actual class. 40 00:03:10,200 --> 00:03:13,440 And that after that, we can define as many methods as we want. 41 00:03:13,800 --> 00:03:20,460 So these look a lot like functions, but they're inside the actual class call and we can see that the 42 00:03:20,460 --> 00:03:22,950 functions can perform any sort of action they want. 43 00:03:23,160 --> 00:03:25,020 They can also take in their own parameters. 44 00:03:25,290 --> 00:03:27,690 Here we have a very simple method call. 45 00:03:28,020 --> 00:03:32,730 And when we actually have these inside the classes, we won't really be calling them functions. 46 00:03:32,940 --> 00:03:37,620 Instead, we'll call them methods in the class or the act on the class. 47 00:03:37,980 --> 00:03:39,240 Here, this one's really simple. 48 00:03:39,570 --> 00:03:42,420 It just is going to print out parameter one. 49 00:03:42,840 --> 00:03:49,560 You will also notice that it takes in the self keyword argument that lets Python know that this is a 50 00:03:49,560 --> 00:03:56,670 method that can use information of the instance of the class, allowing it to actually call self-taught 51 00:03:56,670 --> 00:03:57,390 param one. 52 00:03:57,810 --> 00:03:59,970 In this case, it's actually just printing it out. 53 00:04:01,690 --> 00:04:05,770 So what we're going to do in the next lecture is actually explore object oriented programming and a 54 00:04:05,770 --> 00:04:10,060 lot more detail of code, and we'll start building out some very basic examples. 55 00:04:10,300 --> 00:04:15,910 And then we're going to add more and more topics like inheritance and special methods later on in future 56 00:04:15,910 --> 00:04:16,390 lectures. 57 00:04:16,779 --> 00:04:21,760 OK, I'll see you at the next lecture, or we begin actually cutting out our first O.P. classes.