CSC148 Lecture Week 6

Object Oriented Programming Summary 
   Object Oriented Programming is a style of programming that involves grouping similar idea into classes. These classes are then used as blueprints that can be used to create instances of objects that have methods and attributes associated with them. Objects can then manipulate their attributes and use their methods to perform tasks.

Self
  For all methods associated with a class, the first parameter is always the object itself. By convention this parameter is named self. This then allows you to call the method using syntax like this:

object.method()

which is equivalent to:

method(object)

Inheritance 
   The major idea that we covered in object oriented programming is the concept of inheritance. Sometimes classes will have many similarities and repeated code. Instead of copying and pasting code, which can cause many problems, inheritance is a much better solution. Copying and pasting code would force you to change many files every time you changed your design. With inheritance, a parent class has all the attributes and methods that are common to all the similar classes. For example, if you were designing a program to manipulate shapes, you would have a general shape parent class and child classes for specific shapes like triangles and squares. The parent class would have general attributes like side length, and general methods like find area. The child classes would inherit all this.
   The parent class can implement some methods, but it might not actually know the specific details about methods like find area. In this case, it is not meant to be instantiated, so a NotImplementedError would be raised if the parent class' method was called. The child class would have a proper implementation that overrides the parent class method. Code that uses these classes would then be written for any general shape. It would not need to know what specific shape that it is dealing with and this allows for more flexibility.