Classes and OOP in Python

Key Takeaways

welcome back to our video series on object-oriented programming in Python in the last video we learned what object-oriented programming is and what problem it solves now let's take a look at how we can define our own objects in our Python programs to create our own objects we use Python classes classes are used to create objects practically as many unique objects as we want they also define a type for example take a look at this code my underscore name equals Austin here we create a new variable called my underscore name with a value of Austin behind the scenes this variable is actually referencing an object the type of the object is STR short for string which is a built in Python data type that you've probably used before Python defines a string as a class and in order to create this object of type string we instantiated the string class to instantiate a class or to create an instance of a class just means to create an object from that class you'll hear the word instantiation thrown around a lot in programming so just remember it means to take a class and create an object from that class to make this a little bit more clear I'm going to use one of my favorite analogies let's say we are writing a program that creates doors we'll start by creating a class for a single door this class here is like the blueprint from which we will build all of our door objects the class will specify some properties and behaviors remember each of our door objects will have these and they'll be independent to each door object a door could have properties like height paint color and whether or not it's currently locked it can also have behaviors like open closed and toggle lock we've to find a door class but we've also just defined a new type we can use in our program let's create a door object with a height of 85 inches painted red and we'll say that when we build it it's unlocked we've just instantiate the door class remember that means that we've created an object of type door from our door class and we aren't limited to creating just one just like how in the real world we can build lots of doors from a single door blueprint we can instantiate many door objects from our single door class here I have instantiated one more notice that each of these door objects is unique they both have different heights and colors and each one can either be locked or unlocked at any time we can change the paint color of a single door and that doesn't affect the rest these objects are all independent and they don't rely on the class anymore the class just tells Python how to create the objects here's a question can you think of any scenarios where classes an object could be used in real-world programs in the next video I'll give you some examples and that will learn about how classes are actually built in Python