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Now that we can raise an error of any type, it is time to make our own error types. In this video we show that this is incredibly simple, and needs almost no code.

In this presentation, we continue with several of the classes that we worked on last time. But this time, we create subclasses of them.On the exam, the class question will always be a two-parter. One…

In ths presentation, we will spend the time creating several example classes. This is another major part of the next exam.When we work with classes, it is very important to pay attention to…

As we saw in the previous video, we cannot trust == if we need to test if two variables refer to the same object folder. In this video we show an alternative operator is, which is safe to use because…

Sometimes you do not want to completely override a method. You just want to override part of it, or add a few extra features at the end. In this video, we introduce the super function which allows us…

Subclasses inherit all of the methods of their parent. But suppose you do not want to use the inherited version of a method, but want to define a new one instead? In this video we talk about the…

We have long said that the dot (.) in Python means “inside of the folder”. But which folder? In this video, we show why subclasses makes this question a little less clear. When Python…

Every class must be a subclass of something, and that parent class goes inside of the parentheses. That means that the word object we have been using in all of class definitions is actually a class.…

In this video we show how to define a subclass. It is exactly the same as defining a class, except that now we actually do something with the parentheses in the function header.

In this presentation, we review the class definition. We look at both the syntax (what must be present for the definition to work) and the semantics (how it is processed in Python).Most of this class…

In this previous video we introduced the concept of getters and setters. But how do we force the user to use these when the attribute is so much simpler. In this video we talk about the concept of…

Unlike other programming languages, a Python class has only one constructor, If we want to give the user more flexibility when creating objects, we should make certain arguments optional. In this…

We have seen the None value used in several previous videos. But in this video we finally introduce it formally. In particular, we show why it is so commonly used in object initialization.

In this video, we introduce the most important method definition in any class: the initializer. The initializer is responsible for creating all the attributes so that the user does not need to worry…

Methods definitions look just like function definitions, but we call them differently. In this video we show how to visualize a method call, and we see just how it differs from a function call.

The primary role of an object is to store attribute variables. In this video we demonstrate the easiest way to add attributes to an object. We see that we can also add attributes to class folders as…