I went to a mid-level UC school but maybe could have gotten into Berkeley if I had tried harder. I’ll need you to meet m

We are creating an object a of class int holding the value 2 And and object b of class str holding the value “Hello!”. In a way, these two particular classes are provided to us by default when we use numbers or strings.,So, suppose you are working with Apple iPhone Division, and you have to create a different Class for each iPhone model. For this simple example, let us say that our iPhone’s first version currently does a single thing only — Makes a call and has some memory. We can write the class as:,And our myAccount balance increases by 100 as expected. So it is the same function we have called. Now, that could only happen if self and myAccount are exactly the same object. When I call myAccount.deposit(100) Python provides the same object myAccount to the function call as the argument self. And that is why self.balance in the function definition really refers to myAccount.balance.,Apart from this, Class usage can also help us to make the code much more modular and easy to maintain. So say we were to create a library like Scikit-Learn. We need to create many models, and each model will have a fit and predict method. If we don’t use classes, we will end up with a lot of functions for each of our different models like:,This property of classes is called encapsulation. From Wikipedia — encapsulation refers to the bundling of data with the methods that operate on that data, or the restricting of direct access to some of an object’s components.,But, how are these attributes balance and account_name already set to 100, and “Rahul” respectively? We never did call the __init__ method, so why did the object gets these attribute? The answer here is that __init__ is a magic method(There are a lot of other magic methods which I would expand on in my next post on Magic Methods), which gets run whenever we create the object. So when we create myAccount , it automatically also runs the function __init__,Suppose you are working at a bank that has many accounts. We can create a class named account that would be used to work with any account. For example, below I create an elementary toy class Account which stores data for a user — namely account_name and balance. It also provides us with two methods to deposit/withdraw money to/from the bank account. Do read through it. It follows the same structure as the code above.,So here the str class bundles the data(“Hello!”) with all the methods that would operate on our data. I would explain the second part of that statement by the end of the post. In the same way, theRandomForestClassifier class bundles all the classifier methods(fit, predict etc.),So, what is this self? The way I like to explain self is by calling the same function in an albeit different way. Below, I call the same function deposit belonging to the class account and provide it with the myAccount object and the amount. And now the function takes two arguments as it should.,Yes, you can. But classes really provide you with a lot of power compared to functions. To quote an example, the str class has a lot of functions defined for the object which we can access just by pressing tab. One could also write all these functions, but that way, they would not be available to use just by pressing the tab button.,class Account: def __init__(self, account_name, balance=0): self.account_name = account_name self.balance = balance def deposit(self, amount): self.balance = amount def withdraw(self,amount): if amount <= self.balance: self.balance -= amount else: print('Cannot Withdraw amounts as no funds!!!'),So, now we understand why to use classes and how they are so important, how do we really go about using them? So, creating a class is pretty simple. Below is a boilerplate code for any class you will end up writing:,We should be in the same bracket of hotness, but I’m above you (not height-wise — see expectation #2). Your friends should think “wow, how did you land such a beautiful girl?” while still recognizing that our attractiveness levels are fairly compatible. Make sense?,They don’t wonder if it works well or badly. It just wonders if it works until you deliver better. When you offer better, you provide a better user experience and gain loyal users. For example, on an e-commerce site, the user does not need to know technically how a t-shirt is filtered. We use a visual filter in the interface. Let the design do its job and disappear. This is just a simple example, consider this topic on your own project.,Apart from these a lot of us end up working with classes and objects without even realizing it. For example, you are actually using a class when you use any scikit Learn Model.